Why does 2015 civic vibrate when in reverse with brake on and with a cold engine

The only thing I have noticed is that when I mash my brake pedal it will slowly start heading to the floor.they say this normal. Last time I drove a car I didn't have to lay down in the seat to push the brake pedal to stop.Not sure if the two could be related.

It is covered but the dealer told me he checked motor mounts and they were ok.then preceded to tell me that " they didn't know all about the cvt transmissions and to do my homework and watch for recalls.then they told that my cvt fluid had to heat up to tempature for the vibration to stop. After 5 minutes it does lessen. But none of the other 5 civics I tried out on 2 different lots did not do what mine is doing.

That's a very good point and makes for an excellent argument in your favor! .. Suggest calling Honda Corp office .. See > 2015 Honda Civic problems on this page... Perhaps the Honda tech here will offer some more insight on this issue... He has access to the latest TSB's (Technical Service Bulletins) regarding these vehicles.

Guess what? Took my car back in to dealership again today.It has 36000 miles on it. Still under warranty thankfully. Service manager and mechanic verified the vibration, LOOKED at the motor mounts, said they were fine, and had to call Honda before they can do anything about finding out the problem. Thanks for nothing Honda! Why verify a problem when you can’t work on it to solve it? So much for buying a new car with a warranty!