I'd very much like to see a greater variety of vehicles in game. Aside from a handful of noobs who are lucky enough to get a Miid or Kodaik, there's nothing but Yalms. So here's my little list of ideas to create some useful diversity.
Air Vehicles that do not match the speed of a yalm, but are much cheaper and more readily available.
An extended line of yalms, some that perhaps buff different skills and most importantly, have different appearances.
Ground vehicles that cannot fly, but can come close to matching the speed of a yalm.
To sum up, the yalm looks cool and is a great vehicle, but I'm bored to death of seeing them everywhere.