Well, after going nuts trying to figure out why my engine compartment was leaking something at its passenger side firewall, I narrowed it down to a/c condensation. Turns out, that was the easy part. For the life of me, I just couldn't seem to find the infamous "clogged drain tube" and I finally figured out why. Lol it isn't there anymore!! Probably on the side of the road somewhere, who knows.

The stains left behind were most likely from some spilled, dry engine oil or transmission fluid that was left behind on the firewall. Without the drain tube, the condensation just pretty much went wherever it wanted to, namely the firewall, where it most likely picked up the above mentioned fluids and transferred them to the ground. Hence, the driveway stains.

Big thanks to Massey and Craby for thier help. And as an fyi to the 3800 crew, if you run into the same problem as me, you dont have to get underneath of the engine to find the drain hole. Just stand next to the passenger side of the engine compartment and reach all the way back to where the right side of the evap housing meets the firewall. You'll feel a descent size hole on the under carriage of the housing. That's where the drain tube should be. Let the a/c run and you'll feel the condensation drip onto your hand. Just be careful you dont burn yourself on the header.