Well, after reading the above replies to your post it appears the most popular method to lower the HHR would be the use of lowering springs. That is not to say that it is the best and no one claimed it was the best, but seems only the most popular. If we are talking about certain types of kits, (as you asked about) there probably isn't any one "kit" made for such a project unless you can find something that has to do with air suspension. If you choose to use lowering springs, there isn't a "kit" needed for this function. One just needs to buy springs and install them without the need for lowering kit or installation kit. Let's say that you decide not to go with use of a specific kit and you choose to lower it with springs, then you will need to determine what springs would best fit your desired outcome.

 

I decided to just Level my Panel.

I bought a used set of the goldline rear leveling springs for $75.00 shipped from a member here.

Cost Effective way to go. Watch the classifieds here they pop up used.

 

I went with fully adjustable coilovers so i can raise it and lower it to my liking