My Yeti has developed a rattle sound under the car when I select reverse gear and let the clutch out. There is no problem selecting any gear and no rattle when in forward gears. Would appreciate any help or advice if anyone has had the same problem. 

Cheers

It would help if you said what engine and whether it's  4x4.
Could be a loose exhaust, engine or gearbox mount.

Or a misaligned (too high) exhaust system.

Has work been done on it recently?.

My yeti is a 1600 Diesel, 40,000 miles, which had timing belt and water pump fitted in February. Over a month ago I had a car reversed into my Yeti whist parked in a car park which resulted in some bodywork repair work. will probably have to visit my local dealer but had hoped to have a rough idea of what is required before I let them get their hands on it.

Did it reverse into the rear end?

If yes it could have bent the exhaust to near some bodywork when in reverse.