hello i recently purchased my first Mercedes, its a 1996 C220 and ive noticed a couple strange things about the car that im wondering if they are a real problem or if i am just being paranoid, any knowledge about these things is greatly appreciated.

The first and main concern is that when im driving the car in town the rpms seem normal but when im on the highway and the car is going from 60-70 the rpms stay at 3000 the whole time im going highway speed until i slow to around 50-55, its not really high but it still seems odd, every other car ive ever had would run at 2000 rpms at that speed not 3000, is this normal for these cars? or mercedes in general?

The second concern is a very strange low buzzing noise is coming from my rear view mirror, it buzzes constantly and i have no idea what it is.. but it stops if i put my finger over the holes

help! i need to know if my car is okay to drive or if its about to break on me >.<

 

yes that car 3000 rpm is normal at 60-70 but also make sure you are in D not some lower gear.
buzzing noise is the interior temp fan most likely

 

Just wanted to drop a note to say hi and that we are new to the forum, we look forward to talking to everyone!