ords

If he fixed the sump for what you must have thought a fair price and its been problem free, why don't you trust him? Could be many reasons why he couldn't show you the old parts. Did you say beforehand you want to see the old parts? Did he say how he would fix the sump? As you're not experiencing any problems with the gearbox or getting any fault codes, I'd go with the £120 repair.

I believe the gearbox takes 1.7L of oil, the mechatronics unit takes 1L The mechatronic oil seems to come in 1L packs.

You said in your other post you heard a clicking noise in reverse.

Maybe you can contact this OP for info

Probably something like this https://kinergo.eu/product/dsg-7-03-dsg-7-dq200-repair-kit/

Where did you get the idea that there was a seperate controller, when @ApertureS suggests they maybe controlled by the bcm?

Good that it was a simple fix. Surprised no error codes showed up.

How full was the tank before refuelling?

If it's bad fuel, how can changing the filter make a difference? It will be the same "bad" fuel going thru the new filter. Had you just refuelled? Get it scanned for error codes.

Go to the local store and try before you buy.

When I used to use ECO, mine never came out of coasting mode going downhill and I had to shift to lower gears manually to take advantage of enging braking.

There must be fault codes logged for the supposed corruption? If the ECU is corrupted how is the engine even running?

Agree. Mine only has basic cc but the 1mph increments are very useful. Maybe yours could be adjusted with vcd's coding.

What happens after the car slows down?

You need to find out why s/s is working when it's doing a regen. That's not right.

I'd have wanted before and after performance figures.

Did you ever get it on a dyno as suggested by @Schtum?

Which unit do you have in the car. Which phone?

Are the windows misting up more than usual? Any coolant loss? Do you have a sunroof?

Mine is original from Jan 2013. Has a healthy cranking speed even after not being used for a few weeks. Stop/start always enabled.

Manual or auto?

A fault should have been logged. Would that show the time and date?

Mines been faultless. What age of car are you looking to buy?