How do you know that the modifications you're planning on making to your car will be worthwhile? In an ideal world, you'd be able to test the mods out before you invested in them. And that's exactly what you can do with RSRSpa thanks to its awesome new Stock vs. Modified package. Even better, RSR is offering CarBuzz readers the chance to win an amazing prize. All you have to do is subscribe to our new YouTube channel, and you'll be entered into a draw, with the winner to be announced on Facebook next Monday (August 1).

We discovered just how amazing this experience is last month, when we spent a couple of days at Spa Francorchamps, driving a range of cars, among them a trio of cars that we first drove stock before jumping into the same models that had been skilfully modified by RSRSpa. New wheels, tires, suspension and exhausts made the cars sharper, harder, more responsive and gave them a more brutal exhaust note. Ron Simons doesn't do things by halves. So when modifying his cars, the services of the 2016 Nurburgring 24 Hours winner, Adam Christodolou, was employed to fine-tune the cars' setup. Together, the cars were made faster around the track and more fun to drive.

RSRSpa and RSRNurburg are offering drivers the unique experience of following a few laps in a stock car with a few laps in its modified counterpart. And take it from us, the difference is huge. The Recaro seats offered the perfect combination of comfort and support on the M235i, while the Akrapovic exhaust sounded immense on the Megane RS265. The stiffness of the KW suspension was most palpable in the BMW M3, but it's the combination of the components coupled with the expert fine-tuning that makes RSR's latest driver's package a must try for visitors to the Nurburgring and Spa-Francorchamps.

The lucky winner will get to choose from a Renault Megane RS265 (package value 995 Euros), a BMW M235i (package value 1495 Euros) and a BMW M3 V8 E92 (package value 1695 Euros). They will then have 12 laps on the fabled Spa Francorchamps: six laps in a stock version of the car, followed by six laps in a RSR-modified variant. Track day entrance, fuel, lunch, full-time instruction, one night's accommodation and dinner at Hotel de la Source (valued at 200 Euros) is also included. Video and data from a Race Navigator system, will be provided on a USB stick at the end of the trip. Flights and transport are not included.

The winner will be able to choose from the following four dates: 3rd August 2016 (Wednesday), 27th September 2016 (Tuesday), 21st October 2016 (Friday), 12th November 2016 (Saturday). You've got nothing to lose by entering, and all you have to do is subscribe to our new YouTube channel to be entered into a draw with the winner to be announced on Facebook next Monday (August 1).