I used to run a VXR220 which is the same chassis, albeit more like an Exige than an Elise. Rover or Toyota engined? Rover suffers from the infamous HGF issues, the Yota is stronger but a more revvy drive and can suffer from oil starvation on track.
Long tail S2 roofs are fiddly and can leak, short tail roofs much less so. They're rattly, cold and noisy, and yet the best handling car you are ever likely to drive. Aircon is almost a must-have, and if a daily drive then I'd want the touring pack as a minimum, and preferably the sports pack too. Super touring and super sports packs were expensive options and are highly desirable IMHO. Stereo will always be rubbish regardless ofwhat you do, however it can be improved. The car will need a thorough checking by a specialist to ensure there's no damage to the chassis and to make sure no repairs have been done to it, once it's damaged you'll need a new one at £15K before labour (so basically a write off). Clams are £2K each (there's two of them) so keep that in mind, insurance fixes can be costly!
Very light on brakes and tyres unless being tracked regularly, don't bother with cheapy tyres as you'll kill the handling, budget £600 for a set. It will freeze on the inside in the winter and it'll be freezing cold and blustery when driving with the roof off.
All that said, I'd buy another in an instant, they're simply the best driver's cars available and really get under your skin.