This is not dodgy it is perfectly leagal my dealer has a few people who change there car every year.You are right it has to be modified for the disabled person to be able to drive it or ride in it.My wife has problems gripping with her hands so a simple bolt on spinner to the stearing wheel was all she needed this can be removed when we sell the car so it does not look like the car has been adapted at all.But there is nothing dodgy about it i would rather pay the vat and have my wife free from her problems.