From the back of the book:
Vehicles are more than just transportation for people living on the far flung worlds of the Frontier, and in these pages there are over 100 unique new designs. With everything from bicycles to main battle tanks, from bulldozers to combat walkers, Vehicles of the Frontier has a wide scope. Aliens make an appearance too, with a variety of vehicles from the Kaefers, Pentapods, Sung, and Ebers.
There are also more options for designing and customising vehicles, including catamaran hulls, cyclo-cranes, low-altitude vehicles, and articulated hulls for big tanks. More options for walkers are presented, along with a variety of new vehicular weapons.
Vehicles of the Frontier supports the upcoming Invasion campaign, providing many vehicles involved on all sides of the looming war with the Kaefers.