if the vehicle has no MOT - only a driver ... or if under repair, a mechanic can take another mechanic with him to look for or listen for a fault. Same with trade plates - driver only - no load or trailer to be attached, unless an artic.
MOT Law or hearsay?
I cant find the actual exemption that applies.
Trade plates only cover taxation not MOT.
Trailers can be towed if needed
Trade plates only restricts passengers for hire & reward.
How else would you do test rides when selling the car?
But the passenger being there must fall into the exemption not just giving them a lift.
"Can i carry Goods or Passengers?
The carrying of Goods is not permitted except -:
A load carried for demonstration purposes or a trailer for such purposes.
Reg 38/39 RV (Reg &Lic) Regs 1971
Passengers are not permitted to be carried except -:
The Trade Licence holder or employee and any other person on the vehicle or on any trailer drawn by it provided that the person is carried in connection with the purpose for which the holder of the trade licence is permitted to use the vehicle on a public road.
Reg 40 RV (Reg & Lic) Regs 1971."
So if the current use of a trade plate is legal then a passenger is also legal.
Popping to the shops is never legal.