My car leaked bad. Not from the roof but, rather, from the drains, both front and rear. As some of you may have recalled, I posted a pic showing how water leaked into my trunk and ruined my amps. Obviously, the drains were originally blocked by dirt and leaves forcing water to go into the trunk. When those were cleared and water started flowing into the drains, a hidden issue was exposed. Water started coming into my interior starting in the front driver's footwell. In addition to this, my rear flooded as well.

After much research, it turned out that there was a TSB on the front drains ONLY ON THE 1999 MODELS. This issue was fixed by the factory on 2000 models onward. I got my indy to order the parts needed and had him perform the TSB.

As for the rear leaks, there are rear drains behind the rear speakers. Turned out those pipes were cracked. It took a simple replacement of those pipes to fix the leaks. Doesn't have to be OEM pipes. Any similarly sized tubing would work.

Well, I exposed my car to a brief but very heavy rain this morning and........so far, so good. The front footwell and rear floor area is still dry.

 

UPDATE: Ok, guys, exposed my car to heavy rains. The interior remained dry. In addition to cleaning the drains, checking the condition of the tubes is now part of the routine whenever the car goes in for oil service.

Considering my car has a very low mileage plus excellent exterior condition for a '99, I believe it was always garaged by the previous owner and hardly exposed to rain, therefore, I would safely assume the PO never had the TSB performed and never got the rear drains checked as well.

I would highly recommend to always check the rear drains (I believe the coupes have it too) and, specifically for those with the '99s, to make sure the TSB on the front drains had been performed.

 

What does TSB stand for?

 

TSB = Technical Service Bulletin.

Seems that Porsche found out of the front water drain defect on the '99s that they had issued a TSB on the front drains for the dealers to fix. This TSB had been adopted at the factory on 2000 models onward, therefore, no longer apply to these cars.