My dad restores old military vehicles and they don't need an mot, can be a pain in the arse to get tax for when you go to the DVLA building with just a reg document and insurance document and the person behind the counter is demanding the mot certificate , even had a manager of the place on the phone to his boss for ages trying to get an answer why we thought we didn't need an mot! But yeah if pulled over and it's not in a serviceable condition there are hefty fines to be had