My guess is they're pod racers....
As suggested by @Thunderforge in the comment below, these appear to be from the 2011 Lego Star Wars Advent Calendar:
The Yellow one is a Y-Wing fighter
My best guess for the grey and white one is a T-47 Airspeeder (Snowspeeder)
The Red one looks like a CR20 Troop Carrier seen in the Clone Wars animated series:
The Advent Calendar Manifest on Brickpedia says that all of those craft were included in the Advent Calendar. In fact, if you look at the below image, you will see there was a Y-Wing fighter, a Corvette and a Snowspeeder.
The reason the Snowspeeder was so difficult to identify it seems is because we are looking at the back of it!