TF Prime cars - size compare

If you have been collecting the latest Transformers Prime toys, you will notice that the size and scale of the Deluxe-class car figures have been shrinking with the newer waves.

Below is a comparison photo of the TF Prime Deluxe-class cars I have. From Bumblebee (First Edition), Wheeljack (RID wave 1), followed by Ratchet (wave 2) and finally Knock Out and Vehicon (wave 3). Yes I'm missing Cliffjumper. Somehow not keen to get him...