User blog comment:Visually/RnD is hard and expensive. But you can do it only for rewards./@comment-26761315-20151105183050

Imho, if you want(ed) to win the car, you had to put in the credits to max out the car. So I stopped playing in the RnD. Because if you fail(ed), you probably loose (lost) many credits. And on top of it all it's not a super car.