Version 4 requires a complete new ECU (PowerFC, Simtek etc) to be mapped for UK fuel... looking at about 800quid+ for that to be supplied, fitted and mapped.

Version 5/6 can have the standard ECU mapped using EcuTek software, which is about 500quid to buy the licence and be mapped.

Front bumper, headlights, grill, rear spoiler are different between the models on the outside. Interior is practically identical, there's a slightly different MOMO badge on the steering wheel and the gear gaitor is leather in the Version 5 intead of rubber on the earlier model.


Cheers,
Grant