VCDS scan?

 

I don't have that tool on me

 

Before you rob a bank to pay the stealer, a couple of suggestions.

I think your issue will be with the compressor, probably aged and tired but before looking at it have you checked that you don't have an air leak from the air retaining valve on top of each strut?
They are the brass air fitting where the single air line goes into each strut, just check each one by spraying soapy water over each connection and look for a bubble/s just as you would go when checking your gas line on a LPG BBQ connector for leaks.
Test it whilst compressor is pumping and afterwards after it's been sitting for an hour or two, also check if the vehicle height changes after sitting.
If that checks out have a look at best you can at each strut and check for any visible damage to the strut and boot, you may see something.

Finally, (although I haven't done this myself) check the air compressor itself which will be under the sill on the driver's side, you will need to remove a cover to view. I suspect at the very least the compressor will need a repair kit fitted (look on line).
The only other major mechanical parts I believe that are left in the system will be the air lines and the distribution block which are going to be harder to check.

Tony_B

 

Hi Tony. So far I'm aware of a minor leak on the residue valve on the front left. It's so minor I'm not worried. The compressor on the other hand seems to be activating a lot even when the car is fully raised in comfort mode. I have checked each strut and each boot and nothing seems to be out of the ordinary.

My bet may be the compressor since it seems to be running more than normal and it's definitely visible. Struts seem to be ok having listened for leaks and hisses and nothing is present. Let the car sit overnight and the car doesn't seem to lean to any side except the front left where I know the pressure release valve is leaking slightly. If left for a week then I notice it sagging towards that side. So I know that's leaking. But yeah it may be the compressor. I don't use the car on rough terrain, and I avoid as much bad roads as possible. The first gen touaregs I find their air suspension is very durable but yeah. The car has never been offroad or on any bad roads as far as I know.

 

Here's another...

 

Fixing the leak would likely solve your issues.
It's impossible to advise otherwise until that point.