Best of luck you nor the dealer can't find a simple leak and your going to sue them for what exactly, maybe it's because you didn't check the vehicle out before you bought it, just get your hands dirty and sort it out instead of whinging
Try leaving access open to the area where the water is and get someone to operate the rear wash/wipe, it's probably something as simple as a split or blocked hose either from that or the sunroof, also open the sunroof and pour some water down the drains and see where it exits.
Sounds like an easy fix, find the leak/leaks, should be fairly obvious if going down quickly, keep an eye on your compressor as it won't last long trying to keep up with a major leak.
Is it going down on all four corners, do you have any error messages
Probably hot air from the mechanic
Does he have access to diagnostic software and if so did he tell you the result
This makes good reading
Air Suspension Faults, Diagnosis and Repair
Another thing to check is the engine bay fuse box, lift the relays out one by one and check for burning around the socket areas, this is another common fault and can cause bcem like problems. :mad: :mad:
Sorry for being blunt but of course he's going to be keen on coils, he thinks he's got a muppet willing to pay him £350 for 2hrs work (not to mention £200 profit on the coils as well) and he hasn't got to work on the eas.
Please do yourself a favour and check out the links provided above...
why did you replace the compressor, you need to get the fault code/s read and cleared then you will have a better idea whats going on.
If you search on here you'll find a reference to free software you can load onto a laptop and reset the eas fault, link below, watch the vids and go away and fix...