Joblo.com, the website that previously reported rumors regarding the identities of several new characters to be included in Transformers 4, is now claiming to know the names of the two Auotbot vehicles that were revealed yesterday. According to their source the Bugatti Grand Sport Vitesse is Drift, and the 2014 Concept C7 Corvette Stingray is Slingshot.
Drift may well be the rumoured "Samurai looking to regain his honor by joining the Autobots" character, which would kind of tie in to the IDW Character of the same name.
Nelson, admin of Shoot for the Edit, has pointed out that production names do not always end up being final names .. though it's probably unlikey they would change