Hi Booth11,
Unfortunately I'll be forking out myself for the engine repairs! 
Just like to say I first came across the term detailing in the vw driver mag which did a feature on golf gtis, which I bought before I got my golf. Did notice your black gti though with a paint finish that looks immense! I'm currently doing a bit more research and found this link on youtube:
https://www.youtube.com/watch?v=KP-eAddv2sk
I'd like to get your thoughts (if poss) on the process the guy uses as I was thinking of following it fairly closely to get a good finish on my paint once I get the car back.
Any easy guidance on process and products would be greatly appreciated, bearing in mind I'm a total and complete novice to this! Only just discovered the 2 bucket wash method about a month ago as I wanted to look after my golf once I bought it!
cheers,
Bwiz.
PS - Just realised there's a whole section on the forum on detailing - I'll be checking it out now!
Bad news about the tensioner mate, still you can plan your detailing whilst you await its return.
Glad you enjoyed the vw driver mag feature. Yeah, I'm somewhat fanatical about my car, lol, but to be fair I've had it from new and it's only ever been washed/detailed by me, so didn't inherit any paintwork issues, makes life easier.
Detailing section, yes there's plenty in there to whet your appetite and loads of advice if you have the time to search through. A complete detailing process would include:
Initial light pressure wash
Snow foam (optional) using lance or cannon
Pressure wash rinse
2 Bucket wash - PH balanced shampoo, with grit guards and wash mitt (no sponges!)
Rinse
Dry
Decontamination phase, inc wheels - Tar remover e.g. Tardis, followed by Iron remover e.g. IronX, or combined product such as TRIX
Wash/rinse/dry
Clay bar/clay cloth or clay pad
Wash again, rinse and dry
Polish (DA or hand)
Seal/glaze/wax - can be all or just some of these but wax always last stage protection (LSP)
Wheel protection, e.g Poorboys Wheel Sealant
Dress tyres
Metal polish tailpipes
Dress exterior trim if required
Glass clean
Interior clean
When you've got a spare 2 days that is! But if you start off by getting a good basic washing regime first then the rest can follow.
DA polishing - Haven't had chance to watch the vid link you posted (when I get a spare 15 mins, lol) but best thing is to watch a few different ones to get a broad view. Meguiars vid guides are pretty good. Best advice is to assess paintwork first, start with the least abrasive pad and polish combo and step up from there. In terms of polishing products I favour Poorboys stuff but plenty of other good products such as Meguiars polishes and Dodo Juice Lime Prime. Chemical Guys Hex Logic pads and Meguiars pads are good. It's down to personal preference. Also visit Detailing World forum, there's a lot of info on there and some very useful guides.
Check out these guides too
DA polishing guide.
http://www.detailingworld.co.uk/forum/showthread.php?t=63859 Explains the stages.
http://www.cleanyourcar.co.uk/generalImg/guide.gif.
Various guides.
http://www.polishedbliss.co.uk/acatalog/car-care-advice.html General detailing guides
http://www.detailingworld.co.uk/forum/forumdisplay.php?f=17 
