It was a leaking core. $364 installed with a fluid change. The CAI and spoiler upgrade will have to wait.

 

My wet floor story goes like this;
When I bought it there was a small (apprx 2') piece of weather stripping in the trunk.
The car had just had a new windshield installed. I found some info on line and removed the plastic trim at bottom of windshield and bingo the strip was from there and not having it was allowing water to run in via the fresh air filter.
I reattached the strip and no more water.
Check that strip before anything else ...
the strip is common to fall of and create water leak, but if your sure it's antifreeze that is different, mine smelled a bit funky and was oily from the carpets.
Just something to look at that costs $0

 

Also replace your cabin air filter

 

The Carpet is still a bit sticky from the coolant leak. Can the carpet be peeled back and the mat beneath be replaced? I'm hoping that the stickiness is difficulty with the carpet drying out.

 

00-05 Chevy Monte Carlo Carpet 2 Door 2000, 2001, 2002, 2003, 2004, 2005

Click the above link it has information on how to install carpet and also price on new carpet for your Monte. I hope it helps or gives you some idea...Good Luck