I bought a CLA250 4Matic 2 weeks ago. I noticed the strange vibration since the first day taking it home from the dealer.
At that time, I thought that's because the car's very new and it would disappear the next day or two, but the car continued vibrating everyday. It started bothering me.
One sunny day last week, I was driving my CLA.
It was running nicely until i felt the vibration again, this time it was a bigger one, then suddenly the engine shut off.
My 1 week-old CLA died on the road when I was driving, no power, no response from gas pedal.
Luckily I was able to pull over safely but i couldn't restart the car. so i called roadside service to tow it to the dealership.
I still can't believe what happened to me. It's very dangerous.
If your car's vibrating sometimes, you'd better take it seriously, most likely the vibration is not normal. it could become a huge trouble.
I checked internet and I was surprised to find out there are other people experienced same problems with their CLA250.
Mercedes Cla250 Engine - 2014 MERCEDES CLA250 Problems With Engine
I hope your car's much safer than mine. but if your car's still giving you vibrations, I strongly suggest you to bring it to the dealership and get it checked and repaired when you still have the warranty.
wish you the best.