But ever since I took my Audi to the mechanic to have a hose replaced I've been noticing a lot of weird sounds, and vibrations. The mechanic said "it's a little louder than most A4s I've driven but everything seems to be okay" but since then I've come across some things that have lead into other problems, like a cracked motor mount.

1. When going 45-50 mph I hear a hollow rattle. It sounds like its coming from under the hood, and it only happens once I go over 45. It's not constant, as it comes and goes almost like a wave. Makes no sense to me. However, I've only noticed it on one road. No idea what this could be and the sound continues after I leave this road. Its newly paved, very smooth, with no bumps or rough terrain.

2. In the morning it takes a couple of tries to start it. It seems to be getting worse the colder it gets, and when it starts, the car is loud as hell and vibrates a lot for a few minutes until it warms up. Not sure if this is normal.

3. When going 40-50mph and around 1.5k rpm, the car is noticeably louder and has more vibration. If I accelerate, it immediately stops.

Maybe 1 and 3 have to do with the motor mount, I have no idea. This stuff just makes me hella nervous and maybe I'm making something out of nothing. Any advice is greatly appreciated.