On both the 99 and 03 replaced intake gasket - recommend Prestone extended wear and lose the Dex Cool (caustic to your motor). The black stuff floating around your reservoir... need to flush that out. (Take off reservoir and put some rocks and h2o in it and shake it - flush really good)
99 had electrical problems (no start, intermittent gauges, etc...) after periods of heavy rain.
Sold 99 for 2005 Honda Accord V-6. Best decision ever made. Except bird crap will eat through the paint on the Honda if you let it sit there too long. I had to have the deck lid repainted (on their dime). I think they have a cheap clear coat or forgot to put some on. Anyways, I am going to have a friend sand it down and put some hi-quality clear coat on it.
On 03 I put 100.00 slotted rotors and EBC brake pads on and no problems (suggest you lose the stock rotors - worth the extra money for good steel).
Blower switch relay - behind glove box. Easy fix - did not find signs of h2o like someone mentioned though. I will watch for this during the coming summer.
03 have the front suspension issues - feels like the ride gets harder as the bushings wear out. Must be a design flaw somewhere because it continues even after parts are replaced (twice already). Oh, I have the 225 tires on the car - supposedly the suspension is supposed to be a little more sporty than the 215 tire set up. I never had a suspension problem on the 99.
Currently, the 03 has had about a 5 second pause before the interior power (dash, radio, door switches, etc... work) comes on. I think it is the ignition switch - will check connections and possibly replace.
Radio buttons peeling - not much I can do there except swap it with aftermarket but I really like the radio - do not have any other issues with it.
Car has a rough idle (03), dumped in some Lucas fuel treatment - smoothed it right out. Car runs good now.
Oh, and my dash is peeling on the right side where it comes around the edge to the fuse box panel door. I am going to find some upholstery expert and see if they can re-glue it. I always put vinyl treatment on my dash (UV protection - stuff they use on boats) and tint my windows. I have 89 mustang that is immaculate on the inside because of this.
If your rear window defrost ever quits working and all switches appear to work - there is a relay on the back right pillar that is not noted in most tech manuals - you can buy and replace yourself.
I like the look, handling, and the feel of the car but I do not like the fact it is one thing after the other going wrong... Most of my problems have been eliminated with the exception of the suspension and the current interior power problem (motor still runs).
No paint problems - Ziebart put something on it when I bought the car - darn near bullet proof. I let bird crap sit on it for days and it did not eat through the paint.
Headlamp covers have not faded (knock on wood...), I find that amazing!