Dont know anything about the Dooper but can agree with MINI&MERCGUY about the R56 - you will always hear about the problems on the forum - I have an R56 S and its fine
Also, if you go for the Dooper you can always add upgrades to your car after like alloy wheels, lights, decals, chrome, ICE, etc.etc. If buying the Dooper just spec the extras that are difficult to fit after...