it has just pass mot and this noise is loud its if there someone in the boot of the car knocking ,i have looked and there,s no one in the bootlol
any help will be great

check your exhaust brackets. or it could be a rear damper/coil over broken.

whatever it is its broken loose and banging on the bodywork

Not very helpful, l know but try this.

Locate the + button on your stereo. Press repeatedly until you can no longer hear the knocking.

its probably rear subframe bushes, cost 30 quid a pair and fit over worn ones like a big washer, or possibly radius arm bearings, bit more involved, or check the silencer aint falling off

did the mechanic fall into the boot of the car and someone else lock him there?

check to see if it is him knocking and let him out

probably the last owners trying to get out of the boot when you nicked it ;)

It is the cars way of telling you're driving me too FAST!!! Lol, sorry man. l would say it is something with either a bad tire or a rear axle problem. Shocks, springs something of that nature. I'd look at the shocks first.

l was going to suggest possibly a 'dead' shock absorber but as your car has just passed an M.O.T. this should not be the problem. Then again M.O.T inspectors are not infallible!
Another possibility is your rear exhaust hanger has broken,go to the rear of your car and check the exhaust by giving it a shake. If the rubber mount has broken it will move excessively. It should only move about 1 to 2 cm in any direction. Hope this helps!

sounds like rear exhast brackets OR the muffler is bouncing..FIAT is not known fer dependable cars..it will cost alot in parts..its junk get a nissan or toyota or saturn

If there is a vibration in the car with it, it could be a bad balanced tire or bent rim and the shock is wearing out and proceeding to travel to the top and hit.

Its probably the brackets on your exhaust.
or it could be'' spotty mulldoon' on a skate Bord you knocked over.

as the car has just passed the mot every thing sould be ok but just check the spare wheel and jack ar sucure because l have come across this when a costomer brought a car in

l understand what you are saying l have a 1.7 turbo diesel punto , and as soon as it turn 60 mph it makes so much noise like a 1 litre in 1st year,

if you mean du du du type of noise then it may be your exhaust

Mine does it too, Had it all checked out and they said no problems with anything but....obviously there is - Mine does it too when l have a passenger in the back, ive been assured that it is not the springs, shocks etc and its not the exhaust - Ive cured the problem tho....Im selling it.

l had a simular situation, but it occured when pulling away. it started after l bourgh a new exhaust from Kwickfit.
when l took it to Fiat they found that the exhaust was knocking the axel, so they replaced the exhaust with a propper Fiat exhaust & which solved the problem (they didi a proper job & offered me the old exhaust & l watched them remove the Kwickfit exhaust & put the new on on).
So it could be that.
My adavice is to take the car back to Fiat & get then to check it. The engineer may even come out in the car with u to hear for himeself what is happening.
My car also had it happen when passengers were on board.