Coolant Crossover gasket had melted before I got it. Leaked lots of coolant and overheated. This was difficult to repair, had to remove many parts just to get access to the back of the engine. I'm sure the dealer would have just pulled the engine (and charged me accordingly). In general, it is very easy to work on, though. The basic design of the engine is not too complicated so there's not much to mess up as long as you know a little about cars.
Screws have fallen out of the interior. Many were simply tapped into foam, and over the years have loosened. For this reason, the clip-in windows are difficult to install, but are still watertight.
Since the car is built by hand from the inside-out, a lot of parts don't fit together well and had to be lined up with shims. Over time, some body parts have gotten out of line with each other and have rubbed. There are bolts you can loosen to adjust positioning of the hood and headlights to correct this.
The alarm never worked from the time I bought the car, but I had an after-market one installed. I hear the factory alarm is a joke.
Overall, this is a great car. It's really the best deal you can get on a supercar. The biggest difference between this one and other supercars is the level of refinement. If you want lots of power, but also need fine leather, a Lamborghini is your vehicle of choice.
This should go without saying, but it's insanely fast. Many cars are very fast if you wind them up, but this car gives you power whenever you want it. It feels like you're using a cheat-code on the road. If you feel the need to beat anything on the road, supercharger kits can be found for around $9000USD, giving you 560HP. The stock 420HP for this year is enough for me, though.
People get the wrong idea about handling because they hear of all the people who spin out and crash in these. The crashes happen because these people underestimate how much torque this machine can generate at any given moment. The only time you can realy floor it is when you are pointed straight ahead, otherwise you will get in trouble.
Fuel economy is better than most people think. Around town I get 15mpg, and on the highway I've gotten as high as 23mpg. For an 8.0L engine that gets that much power, I think it's pretty good.
Economically, this car is not as out-of-reach as people perceive it to be. Used ones can be had for as little as $30,000USD. With a clean driving record, insurance can be as cheap as $100USD a month if you shop around and have a beater as your primary vehicle.
The trunk is adequate, but gets hot due to the fact that the muffler is directly underneath it.
The interior was definitely an afterthought. It is mostly made of plastic. On the upside, this keeps the car cost down. The foot-well is not very well shielded from the heat of the engine, so your feet will get hot when you drive it. Although the speakers in the middle give a nice look, they are not sealed so you don't feel much bass unless you install a tube/box/etc. The air conditioning is barely functional. All you have are three vents lined up in the middle of the dash, and then a leg-vent in each foot-well. The leather seats are not vented and so your legs and lower back get sweaty.
The aerodynamics of this car are not very good for the passengers. The windshield is very short, so if you don't put the top on, you will get absolutely blasted at any speed above 50mph. If your hat isn't on tight, it will get pulled off. Also, if you don't have the top on, any AC/heat will get instantly sucked out. If you will be taking anybody with you in the winter, keep a small blanket in the car. The clip-in windows, combined with the top, seal well and are watertight, but impair visibility and fill the trunk if you bring them with you.
Security is an issue for all Vipers made before 1997. 1996 and earlier models had no external door handles and no windows. You have to reach inside and pull the door-handle to open it. The clip-in windows can be opened from the outside, and do not lock. This is necessary so that you can access the door-handle to open the car up, but it means that anyone can do this as well. The only solution to this conundrum is an after-market alarm system with radar.