OK so what about the two antenna from Rock Auto. I understand a longer antenna is for better reception (line of sight) but why is an HHR longer than an Equinox or Caddy ? Is it ride height from ground to roof ? The Equinox sits higher than an HHR but I don't think the caddy does.

 

Fits the design of the car in the opinion of the designer. Purchasing department decisions.

 

So bite the bullet and buy an Equinox or Caddy unit and see what happens.
I would tended to go with the Caddy because of the height of the car.

 

Get any you like is the point. Is there a problem spending $20 on one like came on the car from GM?

 

I have no problems with the original, just wanted to install a shorter one.

 

I would just focus on the screw mount. They are sort of standard, but ones that need adapters should be avoided and you want a good tight "like metal" connection.

 

That's why I'm looking into GM antennas of shorter length.

 

I have a stubby antenna on my HHR. It works fine. I also have a Chevy P/U with an OEM antenna. I make a 100 mile drive once a week and sometimes I take the truck and sometimes the HHR. My route varies sometimes I take the interstate and sometimes a back country road route, it's a little hilly. I get the same good reception with both vehicles on either route. The bottom line is that I have noticed no difference in reception between my stubby antenna and the OEM. I would not argue that under some circumstances there may be a difference in reception but in my case I haven't found it yet.

 

Continuing on this direction of Antennas.
Question on Ft Antenna mast and Windshield Mesh?

I'm in process of changing antennas for modifications in replacing / adding audio system using a Pioneer Radio Touch screen, Rr 5 channel 600W Amp, Sub Spk, XM Radio & GPS Navigation modules for Radio Head.
Removing the 2008 HHR Panel OEM 6 spk system Radio system, OEM Rr Antenna Fin for OnStar & OnStar GPS (2 lead antenna Red & Blue Fakra), and the Ft AM/FM Mast.
The question I have is what's in the Windshield... has the glass mesh around review mirror and looks like it runs along the top of windshield. This is normally AM/FM antenna but the HHR has a Ft AM/FM Mast.

I'm installing an Amplified Stub Shark Fin for Digital AM/FM (stnd), XM Radio (SMB) and GPS (SMA) to avoid needing adapters for GM Fakra connections. Running Antenna's directly up Ft via head liner and A-pillar.
By-passing the OnStar... disconnecting it from Antennas but leaving it all electrically plugged in due to reading it needs to remain installed and there isn't convenient harness configured to bypass.
Was planning a flush flat plug for the Ft Mast hole, but the Windshield mesh threw me since the HHR has no water sensor or other the mesh was confusing.

I've removed all the rear internal paneling & hatch panels but haven't removed the A & B pillar trim or ft header trim to fully drop the head liner and inspect the Ft Mast connection area.
While installing the Audio upgrades, I'm also running a 4mm connection lead Review Camera (170 degree) to Radio Head Screen and Rear proximity sensors to separate indicator. All connections mini, to avoid the RCA sized holes. Camera mounted up very nice, looks OEM next to hatch release. When I have the head liner down, I think I'll add a 2nd Dome light up Ft area to provide a little more light.

 

the wind shield "mesh" is just paint. It isn't anything to do with an antenna.