Let us know how you make out. I had the same issue with a Camry a bit older than yours. I bought it private sale. Ended up replacing the seals in the brake lights. Re sealed all the windows. Replaced all the plugs. Tore trunk apart and sealed everything I could. Had the a/c lines flushed out. Checked the wheel wells. Made a couple other small adjustments. Still every time it rained my rear drivers side floor board would be saturated. Had to shop vac it out all the time and air it out. It was a huge pain in the ass. Other than that the car was amazing. But mold and rust from the inside out was going to be an issue. No body shop wanted to touch it. So I just ended up trading it in. Fully disclosed the problem to the dealer and told them why I was getting rid of it. I still got almost what I paid for it. They just sent it to auction I guess. I hope you figure things out.