strange noise

[sharpie]

i have a mark 2 phase 1 clio, seems alright to drive, but when i stop and get out the car i hear this thumping noise, imagine a tennis ball dropping, the noises are far apart to start with and then at the end speed up and stop.

wondered if anyone had any ideas what this could be?

 

[sharpie]

bump...

it kinda comes from the back underneath of the car

 

[Friction]

1.2 8v by any chance? exhaust popping slightly?

seems common to be honest.