It only happens when car not driven for a few hours and especially when cold. When putting into reverse gears, it has a big jolt.

Is this normal? It seems to get worse.

 

the same thing happens to me, must be the tranny thats cold

 

Mine does the opposite. After I've driven for a long while, if I stop and go into reverse, my trans/rear give off a jolt/clunk.
Must be the way the clutches are set up in the trans

 

Do you use your parking brake when you park?
If you don't, then the probable cause is the weight of the car resting on the tranny.

 

Doesn't sound right. I'd take it to the dealer to have it checked out and get a paper trail started just in case. There shouldn't be any unusual jolts when putting into gear. You have the extended drivetrain warranty but it would be a good idea to have it checked.

 

It doesn't matter what the car is, if you have pressure on the transmission when it is in park, when you release it (ie shift into reverse) there will be a jolt/thunk sound. Ludwigs explanation sounds like it is just pressure on the transmission from the car rolling a little bit (while in park). This happens when you don't use your parking brake.
What GR8G35 is talking about sounds like a whole different issue.

 

i always use my parking brake but my car still jolts a bit

 

I always use parking brake. I used to put it in neutral, let the car rests for a couple of seconds, apply the brake, then put it in park. But it didn't really matter since the tranny would jolt anyway. It only happens when the car is left out for awhile. Once driving around and properly warm up, it does not happen. It only happens when putting in reverse.

 

Alright, that isn't the problem then
Definitely take it into the dealer then.