You probably will disagree with me but I think the 2011 Saab 9-5 would have been a perfect alternate mode for Wheeljack. First off, its quirky. Wheeljack has always been a quirky scientist. Having a quirky alternate mode would emphasis his "madness" as a scientist. Also Saab was once a GM owned brand and despite the fact that Saab is owned now by another company, the 9-5 is hugely GM based and TF could of have easy access to it.