Bad shocks or struts is one possibility.
Maybe that thumping noise is the sound of another car smashing into the rear of your car.
i don't know if this helps but i just had my car repaired tonight and when i picked it up this was a new problem that wasn't there before. i took it back and they said the thumping was caused by a rotor??? that they forgot to tighten? i am not sure i have the name right!
Possibly a broken shock or bad stabilizer bushings
You created a flat spot on the rear tires. Your car had a busted mount or bushing
worn torsen differential
If you lowered the car or had suspension/strut work done you can be rubbing The body in the boot?
No.
You should have someone pull off the hubs and check your bearings to see if they need to be replaced or just repacked
Thumping noises on a car when it starts up could be caused by any number of things. The safest option is to not second guess what the problem is but take your vehicle into a workshop to be looked at.
It is not safe at all to do so.
Check for a broken shock.
A rear tire out of balance.