for my car pete, I would wash it well every 2 weeks, and every month or 2 I would wax it, and every couple of months I would clay and wax.
Kept the car in better shape than most. I dont have the patience or know how to detail like matt, but after every wash, the car always looked stunning.
Also, good wax is important, but in between I loved the results turtle wax ice gave me. Easy to use, and it provided a good, clean, deep, wet look to my paint.
thats after one of the last times I waxed her.
and here she is when I first got her, after the first time I clayed and waxed