Congrats... I fully empathize with you as I have given up on trying to keep my 95 Mystique going, and just purchased an '04 Mazda 6s (V6 5-speed) as my replacement. It's one of the most reasonable replacements for the Contique, very analagous in terms of the value and sleeper quotient as the Contour/Mystique was in it's day. I've been fortunate, compared to others here, with the reliability/repair issues on the 'tique, and my plans were to keep the Mystique as my "winter beater" in VT - but the ABS/TC has died, and that combined with the constant CEL issues are making me ready to punt on the Mercury in the spring.
Surely the 6 will not be without some warts, but Ford is pinning its hopes on the platform for many Ford/Mercury sedan variants in the coming years, so plenty of mods/tricks/aftermarket parts are on the horizon. I plan to keep mine mostly stock through the warranty period (as I did with the Mystique) and take it from there. I haven't had a chance to open up my 6 either, but it conveys a sense of agility and nimbleness normally found in cars costing $10-15K more.
happy motoring,
-Peter
04 Mazda 6s V6 MTX, in service 10/28/03

02 Subaru Impreza Outback Sport 165HP 4cyl auto AWD
former: 95 Mystique LS V6 MTX [11/14/94-5/19/04]