vert = convertible. the second gens didn't come twin turbo-ed, only the third gens. a couple of problems that you can look for are leaking fuel injectors, hot starting problems, turbo shaft play (that isn't rotary specific, so you should know that one), small electrical issues (some speeds of the wipers not working, rear defroster not working, headlights not popping up), and other small things like that.
the way that you check for leaking fuel injectors and hot starting problems are the same. you start the car and let it get to operating temperature. then, drive it for a few minutes and kill it. after that, wait for about 10-15 minutes and try to start it up again. if you smell gas and it won't start, there is a leaking injector and these are not cheap. if it won't start, but doesn't smell like gas, there is just some random hot starting problem. the other problems are easy to identify. just go through as much as you can with the car.