Just found this and figured it was worth a read.

http://www.autoblog.com/2006/07/13/westfield-sportscars-gives-old-miatas-new-lease-on-life/

quite a clever idea ... good for US market as well as the Mx5 (miata) is common over there and has all the approvals for the engine etc. (one of the reasons why lotus switched engine suppliers for the elise)

Great donor -a lot of us are using miatas here in the US for our donors. Nice little lightweight uprights, and good aftermarket stuff for upgraded brakes etc
One of the 'locost' suppliers here have a miata based chassis as well.
Rob

I was heading in that direction to start with but decided to just use the rear subframe for my build, I ws not happy with the performance of the Mx5 motor and went with the CA18DET nissan 1800cc Turbo , so not lack of horse power and will run it on the standard ECU