Audi Pre Sense Warning - Help Please

Just brought the car in for a second time and the dealer ran the diagnosis and found some codes but did not adjust or repair anything and said car seems fine. The pre sense yellow light comes on intermittently and does not stay on and it can take 5 minutes to as much as an hour or more for it to come on and turn off, and sometimes it does not come on for a day or two. So it did not come on when they from the dealer drove it, of course. So I feel helpless and can't understand why they just can't find the problem and fix it or change all the sensors involved and charge Audi, but that would involve too many sensors all linked together, I'm under the impression. They also asked me if I happened to have spilled liquid on the passenger seat, and might have been one of the codes. I never spilled anything except wipe off a bit of sunblock here and there on the surface of the leather using a slightly damp rag, but never soaked the seat while doing this like spilling a drink. Even if this would happen, car seats can get wet and they should not build cars that can't take a bit of this with kids and everything else that can happen.
Any one ever had a similar problem and was able to get it resolved at the dealer? I've now left the car over night so they can test drive it again tomorrow, but may not act up then either. They said they might charge me 145 dollars if they don't find anything wrong as in that case it would not be like finding a faulty part that would then warrant a no charge under the warranty. I'm at a loss with all of this.

Thanks,
Rob

Thanks, worth considering. It started to act up during that time. For the last two months have been using the car more regularly, however last week the garage erased all the codes that came up and since then the warning light has not come back. I've been taking the car out almost every day now and will give it another week and thinking of letting the garage know if things seem fine or not by then.

Here's an update. The dealer finally identified the problem after the fault code came back on two days ago following the clearing of all the old codes three weeks ago. Don't know the history of the car and why there were old fault codes in the first place as I purchased this 2018 car back in February 2020 . So they replaced the sensor inside the passenger seat mat. They removed the seat from the vehicle and disassembled bottom cushion from seat frame. They cut out all hog rings and replaced seat cushion with integrated mat and new PODS control module and harness. This sensor detects whether there is a passenger sitting on the seat and thus affect the passenger air bag being on or off.

Hoping this has solved the issue and will see over the next few weeks. Glad the work was covered by warranty.