What is the best ceramic coating for older cars?

The answer to this question very much depends on the car and what your intent. 

If you have just bought your daughter her first car, it's a ten-year-old town car which is in good condition, but she doesn't like cleaning it, then we would recommend getting a 3-year coating, or even a polymer coating, as she may not keep the car for very long.

If, however, you just bought a vintage Jaguar which you plan on passing on to your daughter many decades from now, we would recommend a ceramic coating which will last a long time.

There are a range of ceramic coatings from a number of different manufacturers, and there is something to suit everybody's needs.