GURPS Vehicles is a 208-page sourcebook for designing and building all types of vehicles, as well as for handling role-playing actions (exploration, travel, combat) dealing with vehicles. Just about any vehicle can be designed, from sports cars to hovercraft, from helicopters to submarines -- the second edition even includes trains, mag-lev and spacecraft. Mecha and battlesuits can also be built with Vehicles, although GURPS Mecha covers that in far more detail.
The system presented in GURPS Vehicles, Second Edition is also the vehicle design system for GURPS Autoduel, and is 100% compatible with both GURPS Robots and Mecha. Note that the second-edition rules differ considerably from the first-edition ones, and are both easier to use and more complete.
Modular subsets of the Vehicle construction rules are also included in GURPS Space 3rd Edition for generic spaceship design, GURPS World War II for TL6 engines of war, Transhuman Space for spaceship design in the Transhuman Space setting, and GURPS Traveller for spaceship design in the Traveller setting.
For those wanting even more options for their vehicles, GURPS Vehicles Expansion 1 and GURPS Vehicles Expansion 2 are 32-pages books offering a variety of new designs, components and technologies. At the opposite end, for those searching for a more simple design system, GURPS Vehicles Lite offers a stripped-down version of the vehicle design system aimed at modern-day land vehicles and helicopters.
GURPS Vehicles Companion is a compendium of vehicles of every type and every tech level. There is also books of vehicles for specific settings, including GURPS Steam-tech, GURPS Traveller: Starships, GURPS Traveller: Modular Cutter, Transhuman Space: Spacecraft of the Solar System and GURPS WWII: Motor Pool.
At TL8+, fuses can be made sensitive enough to detonate at just the right moment. APEX rounds will explode after entering flesh. The impact damage will be limited by blow-through as for any armor-piercing round, but all the explosive damage (x5 for being in meat) will affect the target.