I have a 1990 Toyota Celica GT. Where can i get custom int. parts? Like for example a pink dashboard, pink/black seat covers or a CHEAP body kit. Or just anything else fun to help customize it. I am also looking for rims to purchase.

Totally fitting.
Get some play dough and make your own.

cheap like what? under $20? good luck

most of the best and most innovative mods have been done for relative peanuts by owners who just pulled things apart and used their time and patience to craft a unique bit for their car.