I don't wish to sound like a wet blanket but I broadly agree with robo that this deal should perhaps be reconsidered. Purchasing an A3 via PCP is, I'm sure, not at all unusual, but the exact route you are looking at seems to be somewhat uncommon. If nothing else, the number of parties involved is unnecessarily high and there seems to be a reluctance to give you figures. I'd suggest the car could very likely be purchased at a better price elsewhere. Before you sign I'd suggest chatting to a couple of local Audi dealers to see what they could do.