I have a 2005 neon. The problem is that, after it rains and I try to move the car, a lot of water leaks into the front passenger floor.

The leak in the front will be the ac drain plug blocked it is located on the firewall under your bonnet about four inches in lengh its a black rubber tube on the opposite side of the condenser of your ac unit on drivers side just pull out clean it and put back in it just pushes back into place easy it gets blocked with soil etc and causes the water to back up in the condenser box the only place it can then go is in your car

My 2000 neon would mysteriously get wetness in the trunk and rear passenger side sometimes into the front too. Couldn't figure it out for the longest time (all the seals by the doors looked fine, no holes in the bottom of the car etc). One day I saw on a forum that the tail light seals can cause leaks due to deterioration. I thought there was no chance but sure enough I pulled out the tail lights and the foam seal that goes around it wasn't sticking in all places and was partly falling apart in others!! Some people say to put appoxy or something around the bolts (when the tail light hole fills up thats where the water leaks out I think) but the idea of them being perminantly stuck wasn't appealing for me. So I just went to my local dealership and bought new seals for my tail lights. They were like $20(canadian) each and were so easy to instal. They are basically a sticker!!! Haven't had a problem since. The guy in the parts department said this was a common problem and they always have lots in stock and by me doing it myself I saved the $100 mechanic fee!!!