Karen S. sent this photo to us. It demonstrates just how sophisticated today's cars really are. The new ones can buy service for themselves! Anyone who's ever wasted an afternoon in the service shop knows how life-changing this really is.
Of course, it's also possible that there should have been a hyphen between "car" and "buying" (or even between "new" and "car"). This would have made it clear that there is a service available for people buying new cars, or a new service available for people buying cars--whichever is the case.
But then they might have had to change the layout of the sign and it wouldn't have looked as pretty and ... and... and...
Sometimes, grammar is just a pain. Especially when it means we still have to take our cars to the service station ourselves.