[maxcsr]

Hello everyone I'm in a very stressful situation because I don't know what is wrong with my bmw.
I was driving 25 miles an hour getting to the highway there is a bad road plate sticking out eveyone has to drive through it to go to the highway (NYC)
As soon as I hit that bump I noticed car had a louder sound when pressing gas and it feels as if my power reduced a little. As if I have a custom sounding muffler which I don't.

No codes whatsoever. No rpm shaking. Only i feel as if I have an exhaust leak or the exhaust is touching the frame. Because when I start the car I could feel the whole body of the car as if the exhaust is laying on the frame.
I took it to a mechanic shop that is open 24 hours they lifted it up and looked in the bottom they found nothing.
They are not bmw mechanics they work on taxi cabs but since this was late at night I wanted to see what is the problem before I take it to a bmw mechanic.

We lifted it up and nothing under car making noise or loose. So weird. I think i definitely broke something that caused something to completely sit on the frame so I hear loud humming when i press gas at low speed and if i drive faster than 30mph no sound but I could feel the sound of my engine within the frame by my seat towards the front.

No codes so what could it be?
Couldn't find anything visual and no codes.

Thanks so much for helping me find out what the issue.