Chevy HHR Network - Which Key Fob is right for my HHR? -Remote Start

I have a 2009 HHR 2LT and only got one keyfob when I bought it (used). It is a former rental car, so does not have some of the goodies like XM and Onstar. Also, my current key fob does not have the remote start button. I test drove another similar HHR (also former rental) and it did have remote start, so I was wondering if I could buy a remote start-enabled key fob and see what happens, as I need another one anyway.

My current fob is like: http://cgi.ebay.com/ebaymotors/GM-KE...Q5fAccessories
but I was looking at: http://cgi.ebay.com/ebaymotors/2008-...Q5fAccessories
In the description, though, it says that the car will need the remote start unit for this to work. I just want to make sure that if I do get the second one, it will still work if my HHR ends up not having the remote start receiver.

Also, is there an easy way to tell ahead of time if there is a remote start unit installed?