it is an action that I don't think is too good because you sell a car that you can use to work with that car. You can get more money and it will definitely be safe because the risk is not too high, different from you playing on bitcoin, the risk is very high.
I think that one should invest extra money in bitcoin because investment here is not guaranteed and you may lose your money due to fall in the price. Now you want to sell your car for bitcoin investment, it means that you have no extra money, but think that if you but bitcoin today and the price fall tomorrow and you need money then what will you do? Definitely, you will sell your coins for low price.