*** Not trying to set off another flame war, so please let's not argue about whether LSD is good or bad for the Elise. Knowledgable opinions have been expressed on both sides. ***
I did a search today to determine which LSD units are available for the Celica. As fas as I can tell, Toyota does not offer the Celica with LSD from the factory. They do offer an aftermarket unit through TRD. Looks like it costs about $800 -->
TRD Source. I've rebuilt diffs before, and it can require pretty expensive tools to get it right, but it looks like the clutch packs come pre-assembled on this kit. That would make it a fairly simple drop-in piece (for someone who is used to working on cars.)
Another company named Phantom also makes an LSD conversion -->
Phantom LSD. This is much less expensive, but looks like bad news to me. Apparently it doesn't replace the diff internals, it just adds a spring clamp.
Interesting stuff. I don't know whether I'll drop the TRD LSD in mine. The only track time my Elise will get is when I instruct for track days (about 10x per year.) Since those aren't competitive, the improvement in lap time isn't as critical. Nice to know there are readily available options.