My 245's carpets are wet on driver's and passenger side. I thought it was either a leaky windshield (had two storms) or A/C. I pulled the carpet, removed the plugs and cleaned out the drainage channel with a coat hanger but there wasn't much debris at all. Let the carpets dry out, then ran the AC for 45 minutes, all was well, but the next day both sides were wet again - and it didn't even rain. What do I need to check next? There is a rubber plug on the underside of the floorpan on each side, can I pull it out and leave it out?

I would know if it's the heater core, right?

Also, today the defroster came on all by itself for about 30 minutes then went off. Tailgate harness was replaced 3 months ago.

I finally have a Volvo with the Volvo idiosyncracies we all love so much. My 87 was a bore compared to this one.