This question had come up before, and since I recently had to transport my HHR SS to a body shop I thought I would share how I did it.

Using the factory "oval" frame tie down points I was able to secure the four ratcheting ties downs to the frame of the trucklett with "T" frame hooks.

Here is the front location:





Here is the rear location:



I installed the hooks and straps to the HHR before pulling into the trailer. I clipped the straps to the radiator core support and to the hold down net loops in the hatch area.



I made some ramp extentions so that the lower bumper valance did not get hung up:



To get out of the HHR, I folded down the passenger front and rear seat, left the tail gate ajar, and crawled out.

Here he's all ready to go!



Front and rear straps are crossed, to prevent any possible side movement.

 

Just like the professional snag and drag would do! GOOD JOB!