"New 300CE owner - what might leave me stranded?"
Running out of gasoline? Sorry, couldn't resist.
Seriously, I am also a new owner of a 300CE, '89 model in this case. Have put about 5k miles on it in the past two months. What I'm still a little concerned about is exactly how many miles I can get out of a tank of gas. Every Mercedes I've owned does not record the fuel level acurately. When the low fuel warning light comes on, I don't know how many miles I have left, (No! It isn't something I do regularily. I just have my favorite stations that I like to give my business to.). I'm not sure exactly how many gallons I have left when that light comes on. Do I have 20 miles left, (as in my truck), or 35+ as the owner's manual seems to indicate (assuming a 1.5 gallon reserve tank).