BMW's sustainability chief has a message for car buyers: keep those vehicles longer instead of replacing them every few years. It might seem like an unusual sales model, especially since automakers, including BMW, bring big profits from used vehicles. But times change, and so does messaging.

Per Auto Express, Monika Dernai recently told a media gathering in London that the auto industry is in a position to reduce waste by encouraging customers to hold on to their existing cars and update them regularly.

"We really need to think about prolonging the life of cars; not having a used car market where you sell cars to each other, but maybe take a car and extend its lifespan," she said. "The idea could be that you could freshen up the interior." That's all fine and good as long as a vehicle is capable of receiving over-the-air updates, but that's not always going to be the case.

Instead, Dernai hopes to see "new skill sets in the aftermarket and to design cars so that the seat can be removed and a new seat be moved in - then it's a used car that looks like a new car. It can have the same owner, who then doesn't buy a new car, but we still have a business model as BMW, and the whole of society benefits from that."

This approach could work fine for many owners, especially those who are perfectly happy with their current 3 Series or X3. Still, the appeal of a new vehicle every few years, especially when coming off a lease, will remain strong.

That's the challenge BMW faces with its sustainability approach, dubbed the "circular economy," the idea that society should reuse and recycle products as much as possible to minimize waste.

Dernai and BMW are convinced that private car ownership will not be affected in a circular economy; not everyone wants or can utilize public transportation, but it's still up to automakers to take a leading role in reducing product waste.

What was not discussed at the event were issues relating to cost. How much will owners be asked to pay for that upgraded seat, for example? Can these upgrades be done in a relatively fast manner at dealerships?

There are many questions and unclear answers, but BMW has a long and successful track record in many categories. If there's one carmaker out there that can crack this code with an innovative approach, it'd be these guys.