I think Elan system works as it is - all 60s/70s models entered with S1/2/3/4/Sprint (and the appropriate [Type xx]) so they separate nicely from the M100. I'm not keen on "M100 Elan" because I don't think that's the name people will look for - it may be a common usage nickname, but this is unofficial use for convenience.

By the way, it might be useful to give [M100] to both our Kia Elans???

The bigger point about replacing all [Mxxx] with just [xxx] - I'm uneasy, despite its claimed greater precision. I'm not sure it's an actual problem, but it would also force us into some sort of uneasy M100 Elan title to keep the M100 reference and there could be a tail-wagging-the-dog outcome. But looking through our [M111] and [M117] sets as blocks, I'm not sure we've got the usages totally correct - there seems to be some drift between similar Elise versions between the two codes and maybe a couple of Elise-related versions in [M111] which might have had different new codes we haven't discovered yet??

Re M250 - see http://www.pistonheads.com/lotus/m250/m250-launch.htm for Lotus PR statements that its name was M250. But 118 type number would be useful addition - [118] or [M118]??

Have fixed the Typ M117 typo.