Two plastic bolts. I take mine off (see Robert's Cornish picture) and replace with the standard index plate for its MOT.
Tim
Tim in UK a front number plate is not required on a three wheeler (trike)
I remember looking into this following a thread on the issue last year. I'm sure it was concluded that a three wheel vehicle resembling a car with steering wheel etc. did legally require a front registration number plate. Having said that I haven't heard of anyone being stopped by police in the UK for not displaying one. Bear in mind that latest M3W's are classed as LDV.
Extract from DVLA document V796
"Motorcycles and Tricycles
There are separate provisions for motorcycles and tricycles. Basically motorcycles registered after 1.9.2001 must only display a number plate at the rear of the vehicle. Motorcycles registered before 1.9.2001 can display a number plate at the front but are not required to.
Tricycles derived from four wheeled bodies i.e. saloon cars must meet the normal requirements above for cars whereas tricycles derived from motorcycles must meet the requirements for motorcycles"
As a M3W is more car than motorcycle a front plate is required. In fact if it were deemed to be a motorcycle derivation then having a front plate would be illegal. I know there are plenty of three wheeler running around in the UK without a front plate without problems and have also passed MOT's without.