>>7446138That's probably because the vehicles are the most boring part about Mega Construx. We're experiencing a minifig renaissance, a beautifully cross-compatible system that is fantastic for kitbashing and custom creation. Mega Minifigs are hugely exciting right now and the vehicles are mostly secondary for most people.
Don't get me wrong though, they are doing some great things with brick builds right now. It's just that their minifigs are so spectacular they sorta outshine everything else.