Like many of the bits on the Elise is the electrical system built up from lots of different 'off the shelf' parts. So you'll find some bosch relays, Wipac light units, GM indicator stalks, etc. etc..
It's also a pretty simple system. Not that many parts/wires...
Not too many electrical problems with it on olders cars though, so it seems to hold up OK.
Biggest problems seem to be simple stuff like bad grounding and contacts/connectors after a few years, but a simple clean, re-grease and re-assemble of the affected points usually fixes that.
The Rover K-series alternator tends to fry after a while, but that's simply because it's mounted very close to the exhaust and it slowly cooks the alternator. Should be a non-issue on the US Toyota engine.