Can you file bankruptcy on a loan for a vehicle?

Probably yes. The reason for the "probably" is that you don't file bankruptcy on specific loans... you file bankruptcy in general, and it applies to most debts (there are certain types of debts that are not dischargable in a bankruptcy).

Note that if you do file bankruptcy, you may have to sell the vehicle. In bankruptcy you are often required to sell certain assets in an attempt to at least partially pay off your creditors; you're allowed to keep a certain amount of equity in a vehicle specifically, and a certain amount in "general assets" (which can be applied to a vehicle or to cash or other personal property), but if the vehicle is worth more than that, you would have to sell it.