Numberplate screws for 2004 MINI

[nammynake]

My girlfriend has just bought a 2004 MINI and the rear numberplate has come away from its adhesive strips. I notice there are proper holes to screw a plate on. Does anyone know what size (length and diameter) bolts are required - I'm guessing on those ones with the hinged caps are the ones to use too?

Thanks

[Feirny]

Just the generic ones, we use the signum ones at work but the cheap halfords ones do the same job.