YOu shouldn't need much more than a gallon of base to do your car. I would also find out what kind of paint it is. In the past, all of the touchup paint I bought from Harley was lacquer, but I also know they used baked Epoxy on prodution bikes. If you can't use it with a common paint system it could turn into a problem, and you won't be able to buy the same color from most paint sources in the future.