Breezy_Pete

That would be consistent with freeze-up though, as all of the cabin air goes through the evaporator all the time, I think. 'Illegal' ice presence would explain that flow weakening.

It'll run off all the time the evaporator is cooling the airflow sufficiently, but only usually observable after coming to a standstill.

No excrement Sherlock! (except you mis-wrote condenser when you meant evaporator). As I said, the evap sensor is put there so that the evaporator doesn't get too cold* and thus no ice should form. Maybe through design oversight, or sensor inaccuracy, it doesn't work as intended in all conditions. *That sensor is one form of feedback for control of the solenoid valve that governs compressor activity level.

The flap is supposed to shut every time you select reverse gear, which is arguably why they wear out their motors/potentiometers so well.

Ice shouldn't form unless the evaporator temperature sensor is misreading. Its presence is designed to prevent any such possibility, I thought?

Servicing interval? 505 01 probably ideal if annual/<10k miles or more frequent. No mk1s had DPFs unless retrofitted, I think?

VCDS would presumably offer a compressor shut-off code if you logged the relevant measuring block at a time when it had shut down Or tell you that the compressor hasn't been shut down if it hasn't.

^ Nice bit of info on the difference between retaining clips, here's a photo showing the inner pad on the left, outer on right, from an angle which makes it easy to see.

Door/window oddities won't be relevant to the blower fan, nor will the recirc flap motor, which has probably failed on the majority of mk1s still on the road, unless it's been replaced since build.

Do you know what the original part number is (from having read it off the existing?) I seem to remember that there are a few variants, so as a bare minimum we'd need to know what year the car is to research it otherwise.

Just as an afterthought for anyone and everyone reading; the current MOT test manual can be viewed online. All via one or other link here https://www.gov.uk/topic/mot/manuals

A really clever system could estimate the towed mass by comparing acceleration rate in a given gear at full throttle with and without something connected to the tow hitch (electric skt). ABS sensor wheel speed changes for the rear wheels relative to fronts could possibly calculate rear end loading with and without same connection. Probably neither though, and it's just displaying the (unchanging) design limits if it displays anything at all.

It was me that said it, and I agree! Let me edit my second answer for improved clarity. "No, it won't fail on that".

Thought I'd already covered this. The answer is no, it won't fail on that.

Nobody expects clarity and openness from VW group on the subject of engine oil, do they?

What's probably happened here is that the discs have a rusty lip on the O/D and inside where the existing/old pads have been. The old pads will be worn so they fit between these lips where the new ones will be sitting on them (or trying to). File the rust down and the pads will likely go in. Edit...Or, you bought the pads from ECP and they sold you the wrong ones for the car?

54mm is much more than a pad thickness could be, except maybe on a train.

MOT won't care as long as the thinnest pad has more than minimum of 1.5mm (from memory) meat left.

What is your engine code, and which position on the relay holder does this 109 relay occupy?

19mm, from memory.

What year was the car built? There's a date on there isn't there 230719? Just above Made in Slovenia? TBH ours look like that after only a few months, but we park near many large trees. Vacuuming them out painstakingly is well worth a few iterations. You'll find a brand new activated carbon one has that same grey speckled appearance, whilst a standard one looks whiter and 'cleaner' when new.

54 will be absolutely fine.

Well in that case...

Both photos appear to show standard batteries. Cars without start/stop need to use standard batteries. Cars with start/stop need to use ones that are EFB or AGM type. Does you car have start/stop?

No.