Some people prefer to roll up to a party in an expensive sports car or limousine; others prefer to show up in a Transformer. Luckily for the latter group, Uber is offering customers in Dallas, Phoenix and Los Angeles the chance to go for a spin in none other than Optimus Prime. To promote the June 27 release of Michael Bay’s “Transformers: Age of Extinction, the popular car request service will pick people up in the giant, flame-emblazoned truck the iconic hero transforms into. (Story continues below.) Your Uber experience is about to be transformed in @Uber_Dallas, @Uber_PHX and @Uber_LA