OK, here begins a list of GTI parts I have identified I do not need. As I find more, I shall update the list so check back for updates.
Cylinder head (complete) (105ch)
Set of seats (black with black & grey check) - generally good condition, passenger side front has small bare patch on base (I believe Mikee has the appropriate cover that would sort this out)
Carpet x2 - 1 is generally good condition, the other is a little worn under the driver's and N/S rear passenger's feet but still usable
Pair Girling front calipers (with good pads)
Brake servo
Brake master cylinder with reservoir
Rear brake limiter
Speedo sensor (cable to electronic converter thing)
Sunroof glass x2
Door glass (set) x2 - one sold, one left
Tailgate glass x2 - one sold, one left
Whole host of interior trim panels - if you need anything ask and I'll have a look
Inlet manifold with throttle body, fuel rail & injectors
Air filter assembly & trunking with what I presume is the air flow meter
ECU
Electric window motors (pair) x2
Headlining - grey, no tears - sold
Door cards (set) - either black or black & red (I have both but need one set myself but don't mind which I keep)
Gearbox - one sold, one left - on hold
Engine (115ch) (complete) - on hold
Alloy wheels - 5.5"x13 - set of 5 x2
Pair of vented front discs
Pair of rear drums
Rear brake load compensator
Pair of rear hubs for rear disc conversion
Front bumper
Rear bumper
Bodykit (4x plastic wheelarches & 2x skirts) x2 (one off a red car, one off a black) - red set sold
Front wings (pair) x2 (one pair red, one black)
Exhaust system - downpipe, centre pipe and OMP back box - sold
Pair of front wishbones
No reasonable offer refused (seriously, make me an offer if you're interested, I'm amassing lots of bits I don't need here and it's going to get the point where I run out of space and I don't want to skip anything if anyone can make use of it).

