I have a tillett B6F XL in my mk2.5 and it fitted fine, it sits lower than the stock seat so no clearance issues with the roof and no problems with width, it is also superbly comfortable, I’ve done 450 miles in a day and I feel better getting out of the Tillet after all that than I did with the stock seat, one of my favourite purchases for the car so far. I do have a schroth 6 point harness with it as the stock seatbelt becomes more or less useless (and probably dangerous to use) with the Tillett.