Also whilst i've been looking into the MkII I came across a MkII buyers guide detailing the most common faults with a MkII. Now I don't know who wrote this but would be grateful on your feedback as to the most common issues

The following are mentioned on the site:
Seized Rear Brakes: These were one of VW's less appreciated jokes. The rear discs do so little that the callipers seize up with little encouragement. Replacements are about £65 a side and if the car is a post 88 car you can fit the Mk3 items which are less prone to seizing. Do not be deterred from buying a car with seized rear brakes as they have little impact on the condition of the rest of the car and most Mk2s suffer from this at some point.
Smoky Engines: As with the Mk1, worn valve guides are common on higher mileage examples causing the car to puff blue smoke.
Seized Rear Wiper: The Mk2s aerodynamics suck crud onto the back of the car and this affects the rear wiper mechanism causing it to seize. Inexpensive to fix with scrappy parts or even with some cleaning and WD40, but a good bartering point nonetheless.
Rust Around the Rear Boot Catch: The crud problem (see above) causes the tailgate to rust around the lock and under the trim so look out for this, as bodywork and paint repairs will be required.
Leaking Door Foils: The door membranes shrink and let water into the car like a sieve. Look out for damp carpets and water stains on the door cards. Most Mk2s will suffer this. The fix is cheap but the water could already have damaged the carpets and seats.
Dickey MFAs: As with the MK1, this often malfunctions and is expensive to repair, so check it works before agreeing a price.
Tired Oil Pumps: The 8vs can suffer from oil pump failure, which will be terminal for the engine. If the service history and oil changes are lacking or the engine is full of exhausted oil, budget to replace this as a precaution. The 16v did not suffer from this, as it used a more heavy-duty pump derived from the diesel engines.
Knackered Hall Sender: This lives in the distributor and dies from old age. When it gets hot it will cause the engine to run erratically. The only solution is a replacement dizzy which will set you back £150.
Pinking: All 16v Mk 2 models and pre 88 K-Jet 8vs were designed to run on high octane 4-star and thus will pink unless a timing adjustment is made [see before]. The 16v timing cannot be adjusted and so a V-SAM or similar is required.
Failed Speeds 1&2 on Heater: The thermal fuse on the heater resistor pack often fails causing the loss of speeds 1&2. The resistor pack can be replaced at a cost of £50 from VAG or just replace the thermal fuse with a slightly uprated one from any good electrical shop for £2.50. Again a good bartering point.
Badly Set Up Pieberg Carbs on Non Gtis: This carb was over complicated and regularly leads to poor running, if possible the Weber direct replacement is a good option.
G reg Cars with 90 Spec Kit: Only the 1990 and onward cars came with big bumpers but some owners of 1989 G reg cars fit the kit and sell the car at a premium by claiming it is a late model car so check the cars age on the V5.
Inability to idle: Usually caused by an air leak but often caused by a faulty idle stabilisation valve on the post 88 cars. These are expensive to replace so be wary (£140 from VAG) but can be cleaned if not too far gone.
Heater Matrix Failure: If the heaters blast out damp air then the heater matrix has burst. All Mk2s were recalled to have a pressure relief valve fitted to prevent this occurring. Check to see if the recall has been carried out. One of the hot water pipes that go through the bulkhead should have been cut and the valve added. If not then take the car to VAG and get it done (No expense)
Fuel Pump Hanging off Car: The fuel pump mounts often break leaving the pump hanging off the car by nothing more than the fuel lines (Drivers side, just in front of the rear wheel), which is potentially lethal... Get is fixed as a priority (GTIs only)
Failed Lift Pump: The in-tank lift pump (GTi only) can often fail and will cause the car to hesitate and suffer bunny hopping style fuel starvation before eventually conking out. This can be masked by keeping the petrol tank full, so be wary of a car with a full tank. Luckily the pump is inexpensive at £30 and easy to change.
Noisy Main Fuel Pumps: This is normal so do not be too concerned.
Damage Around Door Handles: These cars are very easy to break into due to the door catch design so look for damage around the door handles and beware of armoured doorplates, which can hide previous damage.
Dodgy 2nd Gear Syncro: The second gear syncro ring fails at about 100k on the Mk2 causing the gears to crunch when going from 1st to 2nd. The solution is a gearbox rebuild or recon box, which will cost upwards of £150. Once worn the problem will not worsen (unless abused) and you can adapt you driving to prevent the gears from crunching (double de clutch, or a small pause between gears). As long as you drive to prevent the gears crunching it will not damage anything else.