At the mo my car is on finance too but I intend on paying it back sooner so I can own outright. Hence no mods on the car until then, which'll hopefully be in 10-12 months time.
I've heard of some dealers not twitching when Revo remaps have been mentioned. Is VWUK likely to be in the same boat as SEAT uk? Especially given that they're all part of VAG?
This is also one of the reasons I had against buying a mkv. If I bought a mkiv GTI, I could get it serviced locally for a cheaper rate and still be able to modify it without hassle.