I don't know how old the hoses are, I did have a major tune up done on it about 2 1/2 years ago. I needed to replace the distributor cap and it had been awhile since I had a tune up so I did that, as well as a transmission service and got all new plugs.

I do keep an eye on the oil and it looks pretty clean to me. And I really don't seem to loose oil. It's about half way between full and low.

As far as I can tell, I can't see any oil in the overflow tank. What I do see is the coolant level going down.

I had a transmission guy driving my Miata several months ago and I was describing the symptoms of my Benz to him and he said it sounded like a water pump. This was before I drove it that one time without there being any coolant in it. I did take the cap off the overflow when it was really hot, but it was empty. I don't think anything happened, because nothing came out.

Which belt should I check? I'm not afraid to go looking around under my hood.

One other thing I have noticed under there is the long black cover over the plugs seems to be loose or it won't shut down all the way. I don't know what the deal with that is but I guess it does not affect the driveability of the car.