that auction is for one wheel only.... your car will look very silly with only one wheel

ask him for the numbers off the inside of the wheel.... pretty sure that Polo GTI alloys shd be 16"....

BBS "RS764" = wheel make and model, "6/1/2J" (6.5J) = wheel width, 16H2 = 16", ET45 = offset
pls note: ET45 is 15mm-7mm too narrow (should be ET30-ET38).... since the wheel was already 12.5mm narrower than it was supposed to be 6.5J, not7J, I deciced to add the FULL 15mm back onto the offset....
That said, I was able to run these wheel straight away despite the ET45 offset (and I drove to Paris and back like that, not a prob!), but needed wheel spacers to make it look right...
smaller than 15" and you might hit probs on your brake caliper clearance... I know 15" was the smallest I was advised to go on mine....