This is mentioned in several old threads, but no, the HHR does not really work for pin hauling. As was mentioned above, you can do the trick of taking the backbox hinges off and sliding the backbox down towards the front of the game to gain just enough clearance. Different brands of games fit differently, of course, but with a 90's B/W game you have just about 1/4" of clearance when you go this route.
I've hauled about 8 pins in mine, and most times I just behead the game completely, as it's necessary later on to get them up my nasty staircase. You may just want to go that route. It's really not *that* bad once you do a few....
I love my HHR, and they are awesome on fuel. I've never even thought they were too small in any regard other than the back hatch height, but I do wish the dang windshield was taller! If you're 6' or taller, you kind of have to lean down to see. hopefully they'll correct these two things on future models....