Hi I have recently upgraded my performance and am having some difficulty in obtaining the correct upgraded calipers. My current vehicle is a 1.9tdi 2004 Avant Final Edition. I require the optimum calipers which would manage around 210bhp. I've looked at the 2.5tdi C5 and the only difference I notice is the size of the disc as mine is 288mm and the 2.5tdi is 320mm, the piston sizes are 57mm. The other option is the 2.5 tdi quattro model which has two pistons and the same sized disk. What i need to know is 1. If i utilize the 2.5tdi calipers on the standard model will there be much noticeable difference as the pistons are the same size as my current ones. 2. Can I use the Quattro calipers and if I so is it a virtual straight swap or will I have to do some reworks etc and will it be the case of just swapping over the carriers and bobs your uncle. Much needed help.. Thanks .