Elise and Exige have completely different manufacturing processes for their bodywork. The Exige is hand laid and therefore thicker and a bit tougher. Elise bodywork is vacuum molded and therefore thinner, lighter and a bit more fragile.
Vacuum-Assisted Resin Transfer Molding is the term. 'vacuum molded' implies it is made like an RC car body, hot-formed plastic on a vac table, which isn't the case.
It's just fiberglass mat that is squeezed in a set of molds, put under vacuum, and resin gets pumped in.
The Exige clams are made with more manual labor.
We should really stop perpetuating the claim that, since the driveline is Toyota, it is therefore reliable. I would dare say the 2ZZ is one of the more problematic Toyota engines. Wiped cams, oil pump gear explosions, etc. Not to mention the Lotus- caused problems- dying at hot idle return (ECU tune), oil line ruptures, etc.
And from what I am seeing, the clutches do not last nearly as long as you would expect a toyota clutch to last.
The good part is, that when it does break, the parts are cheap. If you can do the labor yourself, it isn't ever going to kill the pocketbook. If not... get some friends.