Got an email from Paulo Silva the other day about the project he's working on, converting MSX and ColecoVision games to run on the ZX. Well some progress has been made with the game "Road Fighter" originally on the MSX. He's sent me a package of the work completed so far, which you can grab here. The pack includes the MSX-version.
I think it's a nice little (or perhaps large) project, and if you'd like to help out then please contact Paulo.