Here, CLOSE this one too!

 

Check the drivers side bump stop , it's adjustable, mine was out 5/16 of an inch

 

..................

 

Yes they're the rectangular rubber bump stops on the sides.

 

I seem to recall in another thread of your's that one of your liftgate struts was broken off.
Hope that the liftgate itself isn't bent or warped because of that.

 

On the hood adjustment lower the bumper on the high side, then drop the hood down and close it
If that side is still high, manually push the hood downward to see if it is not seating on the lowered bumper. If not then you may be too low on the bumper or need to make a small adjustment downward on the hood latch as well.
I mark the current latch setting with masking tape on the edges of the latch plate so you can see how much you have moved the plate in either direction.
I take extra time in adjusting to get any issues as close as I can so don't be in a big hurry. The front of the hood is the only reasonable adjustment available.
When done. grease the front latch contact points.
I also put a dab of silicone grease on all the hood rubber bumpers.

Do you have a Carfax or Auto check that shows if this HHR has been in any accidents?

These issues could be the work a some Sloppy body shop in the past.

SF

 

.......................

 

You could try loosening BOTH stops then close the gate. Remember: one out will force the other in.

Visually inspect the hinges, if 2 thing rusted out maybe 3 things did.

 

................................