Many states offer lemon laws protecting consumers from automobiles that turn out to be a lemon requiring a new vehicle of the same type be provided if it needs to be repaired so many times withing a certain time period. Be sure to check your state.
A good way to find old parts for collectible antique cars is to scour junk yards and other peoples yards looking for a model just sitting there getting rusty that they may want to get rid of.
Regular oil changes help avoid sludge build up as the car gets older. Consider using synthetic oil, it really does make a difference in the life and quality of the vehicle.
Call individual dealerships for quotes before going. Be sure to get the name of the salesperson and verify the make and model number of the specific car before you get off the phone. This will give you an advantage and may get you a better rate.