Emission Systems For Cars And Trucks Cheapest Parts On the Web

i have a 1990 toyota celica that i have fixed up a lot. i love this car to death but i have an ongoing problem that i can't seem to figure out. for a long time now, whenever i wash my car, i have to put blue painters tape around the windows because water gets inside it and rolls down my door panels and stains the vinyl. well on my drivers side, the water comes in by the front of the door, like below where my mirror is. my dad and i have been trying to figure out exactly where the water comes in from for the longest time. it does the same thing on the passenger side and after i dry my whole car when i get inside there is water on both door sills, on both door panels,etc. it's really annoying that we cqn't figure out why or where its coming from. the weatherstripping is old and i'm not sure if replacing it will help.