As Chadahar mentioned... I think his point was to be sure the switch was turned on, because if its not on, these will not work. I found that out the other day on my 88' 300SEL. I dont think he was really aware that you were already familiar with that operation of the car.

Unless your low fuel light is on when you have plenty of fuel, I think Tinypanzer answered your question on the airbag/low fuel light, so that was a pretty good bit of advice. The airbag light being illuminated when the car is running should have nothing to do with the seat not working. It should not be illuminated with the car running. Ironically on mine, the light dont come on at all, which is not right either. Perhaps a bad bulb. I too dont think it would come out for no reason, but it does signal a problem. May just need to be reset by a professional.

Also, as Tiny mentioned, as far as the low fuel light being dim, like mentioned, it could be the bulb. Since you have owned 30+ Mercedes (I have owned only 3), you may already know that the bulbs on these cars grow dimmer over time.

Sometimes people just want to verify some information, because some people that come here may have never owned a Mercedes or know their quirks.

Hopefully someone here will have the answer you are looking for, but dont be too discouraged if they dont.

Good luck!

BTW, that is a super nice car you have there! Mine has it beat by 100K miles more and its still a nice car, so yours could stay that way for many more years... these cars are tanks.

*just want to make sure that the timing chain/tensioner/guides/rails are up to date on that particular engine despite low mileage, because those guides/rails weaken over time - if one of them break, its disasterous for the engine.... but you may already know that too.