BMW's list of car models is extensive and goes all the way back to the 1920s. The first BMW produced was called the Dixi, which was a licensed version of the British Austin 7. And that doesn't even make this list. The second BMW car, the 303, doesn't make the list either despite being the first BMW to feature the signature kidney grill. Although it is historically significant, we know a lot of people don't know about the 303 because of the sheer number of complaints about the size of the kidney grill on the latest 7 Series.

BMW has a strong habit of building special editions as well as prototypes that go a step too far to be practical and cost-effective to mass-produce. The brand also likes to swap V12 engines into cars and keep them locked up in a secret location, seemingly, to taunt the hardcore BMW fans with. Then there are the versions of BMW cars created by other companies, including Alpina, and tuner versions from companies like AC Schnitzer, Hamman, and G-Power.

That makes it hard to pick out a concise list of rare BMWs that tend to fly under the radar. So, we've taken the approach of picking out the ones we simply find the most interesting or eyebrow-raising. There is, of course, a V12 swap in there of dizzying proportions, BMW's third car, which was an absolute barnstormer, and some M model variations that range from the bizarre to the so rare it might as well not exist level. We'll start with something bizarre though.

BMW M3 Truck

BMW didn't toy with the idea of an M3 truck just once. The 1986 BMW E30 M3 Pickup came into existence when BMW's Motorsport Department saw potential in the car for delivering parts, and we assume it was thinking of parts that were needed somewhere in a hurry. The M3 it converted used the smaller displacement 2.0-liter "Italian M3" 4-cylinder engine and was actually used on-site by BMW for around 25 years before being retired in 2012.

The second one started out as an April Fool's Day prank to play on BMW enthusiasts, including 'spy' shots from the Nurburgring and a press release. It's still being used by BMW on site but isn't road legal.

BMW X5 LM

We've all seen the early 2000s BMW X5, but very few of us has seen the one BMW shoved a BMW V12 LMR engine under the hood of in the name of promotion and fun. Because the car didn't need any restrictors to comply with racing rules, the 6.0-liter race car engine in the X5 was able to produce around 700 horsepower - a hundred more than the sanctioned race car it came from. It even got a timed run around the Nurburgring helmed by the legendary racing driver Hans-Joachim Stuck. He clocked it in at 7 minutes and 50 seconds and hit a reported top speed of 192 mph. BMW has still got the X5 LM and occasionally displays it in its collection of V12-swapped cars.

E21 BMW Baur 3 Series

Before the E30 was the E21 3 Series, and BMW didn't make a convertible version. A Stuttgart-based coachbuilder named Baur convinced BMW it was something that would sell and the companies teamed up to make a not-quite-a-convertible E21. The top panel comes off like a Targa, but the soft top covers the rear-window area. When down, the soft top sits on top of the trunk so no storage space is lost, and the B pillar on each side is connected by a nice thick metal bar.

Beur actually continued to modify the 3 Series through the E30 and E36 generations, but there was never an E46 given the Baur treatment.

E34 BMW M5 Winkelhock Edition

BMW approached two racing drivers in 1991 to design their ideal version of the then current M5. Former F1 driver and two-time Nurburgring 24 hours winner for BMW in an M3, Joachim Winkelhock, went down the road car for the race track route. He deleted anything that wasn't deemed essential including sound deadening, the fog lights, the rear seat headrests, and vanity mirrors. He also opted for the smaller US-spec gas tank and a lighter battery in the name of saving weight.

The 51 Winklehock special edition M5 cars also came with an M-Technic II steering wheel, shift knob, and park-brake handle, and red seat belts as well as wider rear tires. They also all came in Jet Black paint that contrasted strikingly with the Sterling Silver metallic coating the lower bodywork.

BMW 700 Sports Coupe

You could argue the little-remembered 700 Sports Coupe as being the most important of the post-war BMW cars. Austrian BMW importer and racer Wolfgang Denzel convinced the BMW board to allow him to have a more stylish version of the 600 model to sell. In 1958, Giovanni Michelotti was commissioned to design the new body and it was then refined in-house by BMW stylists who also developed a sedan version. BMW's head of engine development also got to work, squeezing 30% more power out of the air-cooled engine before the 700 was presented at the 1959 Frankfurt International Auto Show.

It grabbed everyone's attention and, as a result, BMW received 25,000 purchase orders from customers and got them out of dire financial straits. The success of the 700 staved of the forced merger with Mercedes-Benz. That paved the way for the Michelotti designed New Klasse sedans that solidified BMW's identity for building sports sedans and ensured the company would survive well into the future.

BMW M3 CRT

The CRT edition of the V8-powered E90 M3 may as well be fashioned out of pure unobtanium. Only 67 were made, and CRT stands for Carbon Racing Technology. BMW shaved 155 pounds off the normal version by using plenty of carbon-fiber, but with prices reaching around $300,000 to buy one and a regular E90 M3 being a fraction of the price, it's now just for the BMW fetishist with more money than they really know what to do with.

BMW 750iL V16

Back in the late 1980s, BMW's flagship 7 Series came close to getting a monstrous V16 under the hood. In 1987, Dr. Karlheinz Lange was head of BMW's powertrain department and enlisted the man behind the 750's 5.0-liter V12, Adolf Fischer to help. On the dyno, the new V16 developed 408 horsepower at 5,200 rpm and 461 lb-ft of torque nice and low down at 3,900 rpm. It was also as smooth as fresh cream, so all they had to do was fit it into the 7 Series.

Unfortunately, that's where the problem was. The powertrain department had to redesign the car for it to fit. Engineers went to work on a prototype and had to do some drastic work to get the V12 to function properly, including fitting a larger manual transmission and using two smaller radiators they could only now fit in the trunk - hence the hand-built fiberglass scoops in the rear quarter panels. The prototype was named Goldfish because of the dark gold paint.

The prototype hit 60 mph in around 6 seconds and kept going to 175 mph. In the end, it wasn't practical to build, despite how promising the V16 turned out to be, and never got the green light to move out of prototyping.

BMW E34 M5 Touring

It's often forgotten that when the E34 M5 came out, it wasn't much loved. It had the same power as the previous generation but more weight, so it didn't feel as lively. There was a refresh in 1995 though, and that came with the final iteration of the straight-6 from the legendary M1 and more importantly if you wanted one, more power. The Touring version of the E34 M5 was a rarity with only 891 units produced and all of them were left-hand drive.

Even rarer is the E39 Touring, mainly because it didn't go into production. As far as anyone can tell, only one prototype was made so if you see one on the road then its bound to be a standard 5 Series Touring that's been converted.

BMW 328

The 328 was born during an unfortunate time for Germany. It was produced from 1936 to 1940, overlapping the start of World War II and was a period of time that Germany, as a whole, isn't eager to remember. Others do though, and in 1999 the 328 made the top 25 in the Car of The Century awards for the right reasons. The 328 is a racing legend that won its debut race at the Nurburgring and went on to take over 100 class wins in 1937 alone. By the end of its run, it had won the 1939 24 Hours of Le Mans, the 1939 RAC Rally, the Alpine Rally, and the Mille Miglia. In 2004 it even won the modern-day version of the race for classics, making it the first car to take the win in that and the original.

An interesting postscript to the story of the 328 is that people from the British Bristol Aeroplane Company retrieved BMW's technical plans and disguised one of the Mille Miglia 328s as a Frazer Nash car to get it home. They set up Bristol cars and then persuaded Fritz Fiedler, the man that designed the 328, to work for them.

BMW Z8 Alpina

Most car enthusiasts know about the Z8 and how the exterior was designed by Henrik Fisker to evoke the ever beautiful BMW 507. What's lesser known is that Alpina took a swing at building a touring version of the Z8 and, while the company usually adds power to a BMW model, it chilled the Z8 down and softened it up. The Z8's standard 6-speed manual and 4.9-liter V8 were dropped in favor of a 5-speed automatic and a 4.8-liter V8 for a more relaxing, but still athletic, ride and was given some custom wheels to set it apart visually. Z8 models go for crazy money, but the Alpina Z8 manages to hold a premium due to being even rarer. Only 555 were built in the Z8's final model year.