I think in the near future, bitcoin currency will be adopted by the automobile industry as a currency for payment. But for now I do not see any problem for as long as you had enough btc then you may just have to convert it to fiat money then you can buy the automobile you want.
Buying a car is an easy problem when we have money / bitcoin. We only calculate how much bitcoin we have and then switch to bitcoin exchanges, if it's enough to pay for the car we want, pay and be ours. Is that simple? The problem is that bitcoin that we have is not enough, then we save it again and pray that bitcoin will rise as high as the sky so it is enough to buy a car.