"Speedster" is a terrible name, but I could not think of anything better

so there are buffed units cards for damage, armor, vision, and range, but what about movement? I would love an AA with 4 movement in some of my decks!
Here's what i think the rarity should be:
Fighter - Ultra Rare
Heli - Rare
Recon - Ultra Rare
Light Tank - Rare
Heavy Tank - Common
AA - Rare
Artillery - Ultra Rare
Infantry - Ultra Rare

Not exactly sure how the costs would work. If they are cheaper than the unit itself (since you are limited to buffing that one unit instead of any that the card can be applied to), then i'd say:

Enlist cost (plus) 20-30

I also would like to see a card similar to "rally the troops" for vehicles/aircrafts. Something like Nitroboost :Þ giving +50% speed to 3 mechanical units for 2 turns. Ultra rare, ~35g.

Oh thats a good idea but it should for every mechanical unit (Air and Ground)