Now, here is an ad idea after looking at the Giant ad. I think it is truthful and yet parodying the GM ad:

A picture showing a passenger in a truck/SUV is stuck in a traffic jam looking enviously at a cyclist who just zipped by (possibly with a wave from the cyclist). And the tagline could be "Traffic Jam Sucks", "Time is better spent moving" or something in line of that (literary is not my strong suit).