Well, I'm too lazy to write a long answer, so I'm just going to quote someone Nathan:
"I could write volumes and not really answer this question - then the next guy to come along would probably disagree on half of what I said. It really depends on several things: 1) what you want to get out of the car, and 2) how much time/money/energy/blood/sweat/tears you have to put into the car.
The first thing to ask yourself though is: "How much do I have to spend?" If you only have $4 or $6 k or so, I'd say stick with a g60, and keep it stock until you have some extra cash. But if you have something like $8 or $10 k to spend, and you want an SLC, go for it. You can find SLC's for less than $7 or $8 k, but they will probably have a lot of problems. Plus, it is really a good idea, imho, to spend less money than you have on the purchase of the car - that way, you have a bit laying around to cover anything that comes up immediately.
The g60 Corrado has several things going for it. It is lighter, has almost as much power stock, is cheaper to buy and maintain, and is much cheaper to tune. The SLC is a nice car out-of-the-box, but it is more expensive, heavier, and much more costly to tune. Of course, if you are filthy rich, the VR6 engine will have a higher potential output. But, imho, even that point doesn't mean much. A fully tuned g60 will have you near 200 hp and 200 ft/lbs of torque, which is, again imho, about as much as you want in a front-drive street car.
Here's an example - $500 spent on tuning a VR6 will get you a set of cams and a chip. $500 spent on a g60 will get you a stage IV kit. The end result in power will probably be pretty similar, even though you had to spend a couple grand more to get the SLC in the first place.
When buying any used car though, the most important thing to consider is the care the previous owners gave the car. If they beat it up, stay away. If they tell you they did x, y, and z to the car, make them show you reciepts for the work. Don't get taken. There are a lot of Corrados out there that have been beaten to death, especially g60s.
There are several common problems to look for with each car. The most important thing to look for on a g60 is the health of the charger. If they can't show you a reciept for a recent rebuild, then figure on spending about $700 right off the bat to get the charger rebuilt. It is very very very easy to permenantly damage these chargers to the point where they aren't rebuildable, so the best insurance is to rebuild before they show signs of needing it.
Do a seach, this subject comes up ALL the time. If you want to get an idea of the problems people are having with these cars, and what people are doing to them, go read in the vr6 and g60 technical forums for a couple weeks. Typically, those forums are a lot more information-rich than this Corrado forum. Also, go read up at
http://www.corrado-club.com - there's a ton of good info there, too.
-Nathan Enders-"