For example a part that when active creates mound of dirt underneath it as it moves along across tiles (plow), but slows a vehicle significantly (or maybe just adds a ridiculous amount of weight) A part that when active remove rubble or wrecks and leave behind clear terrain (dozer blade), maybe some kind of futuristic autobuilder that creates floor tiles beneath it when supplied with lots of planks and nails or maybe pebbles and gasoline (for fixing bridges or building roads through swamps).
I like.
Would love a well drilling truck that could create wells in certain areas.