No, but it wouldn't be very difficult to make: slow speed (compared with wheeled vehicle) but almost perfect cross-country potential (better than 4 wheeled), lots of armour (when you are a huge target, there is no alternative) and lots of weapons. The exact mix depends heavily on your setting and how much advantage you could want to give to your mechs. They are not real world vehicles and are very different from one setting to another. Your best bet would be to take a mech listing from another game and translate the speed, armour and weapons ratings into MSPE, maybe adding a few skills. Just my 2 cents as I never really tried.