First you need a scan of the TCU, preferably with Vagcom or from a dealer to get an idea of the faults. Secondly, are you sure the seat has to be removed and the footwell carpet can't be just pulled back along with removing the trim piece where the carpet meets the door seal? HP24 was never a great transmission but there are some reputable rebuilders that do a good job, one of them is Tozo from Audizine and someone here probably has his E-mail or #, he's located in Chicago area.