My wifes 2002 SSEI Bonneville is starting to give me a major headache/concern. It has a major water leak somewhere on the passenger side.. The front passenger side is soaked along with the back. Since it channels all the way back to the rear seat. I can't determine if it is coming from the front or the rear of the car.

I have traced the sunroof drain tube on the passenger side to the trunk/cargo area.. It doesn't leak. The headliner also does not get wet.

The front floor board has a plastic liner with foam padding on it behind the carpet going up the firewall. It is wet fairly high up on the foam padding which leads me to believe this is it'* origin although not certain.

I have fixed all four doors from previous leaks and have check the door seals numerous times on heavy rains. They are dry as a bone.

Both front and rear areas are soaked thoroughly. I have lifted the rear carpet up with the front end on ramps. Then take a shop vac to it and got about 5 gallons of water out of the car. I need to get this fixed before I start getting any rust issues.

Any help or ideas would be of great help to me!!

i have the same thing goin on with my ssei on the driver side same problem same issue have been trying to figure it out and have heard many things that could cause it
1) sunroof drains
2.) pin hole in the fire wall
3) hole in bottom of car
4.) door seals leaking
5.)the door skins themselves under the speakers
6.)or a rust through in the rear wheel wells
have not been able to exactly pin point mine yet but it sounds like you have ruled out the same items as me. ill try a couple other thing today and maybe we will have an answer

Well found the problem today after a few hours. A while back the car went into the dealer for a security/ignition issue. They ended up taking our dash out and repairing the wiring harness going to the ignition switch. When putting it back together. They did not hook the front passenger drain hose back up. So now our carpet is ruint because of their error. I kept thinking it was an error with the car not human error. oh well, to late now. Hopefully there won't be any rust issues from this.

Now I have to figure out the trunk leak. Doesn't seem to be coming from taillights or spoiler. Yet the trunk lid liner holds a ton of water. Any ideas?

well thats nice make em replace it i would. i need new carpet in mine as well. as for the trunk i have no clue mine was fixed by the dealer before i bought it but no idea what they did to fix it but after i wash the car or it rains when i pop the trunk water comes out from behind the light on the lid and runs in but only when opened. i would check the weather striping around the opening also check around the back glass that seems to be another place it comes from

Climb in the trunk with a flashlight and have someone run the garden hose of the trunk. I found that mine was leaking by the latch and percolating up from under the trunk seal. I replaced the seal and ran some clear RTV on the seal welts in the drain channel between the trunk lid and the rear quarter panels.