Thanks to Gettodeath for providing the pictures below taken Saturday at San Pedro, CA where Transformers 2 was filming. They show Optimus Prime, the mysterious Ice Cream Truck, Ironhide and NEST vehicles. Gettodeath suggests that Stinger and Wheels are the two Transformers that form the ice cream truck. Since their alt modes are not even close to being verified, it’s actually a pretty good theory since both TFs are on the Bethlehem call sheet.
I am thinking the scenes being filmed are a prelude to whatever action was filmed in the interior of Bethlehem Steel. If you look at the first picture, you will notice neon Chinese signs that look very similar to signs put up at Bethlehem Steel. In the second picture, at the end of the road is a Chinese sign that looks identical to the front entrance sign that Jason took back in June, but imagine it after you drive under it and look at it from behind.
Update: Below are two additional pictures provided by Gettodeath. One is a close-up view of the ice cream truck and the second is the mysterious silver Corvette seen here and there.