I have been toying with a Home Brewed rule that relates to troops moving along side a vehicle in a screening action. What brought this about was playing a few small games by myself to test some rules I came across this situation several times. I would move a unit next to a vehicle to take advantage of it being screened. However once the vehicle moved the troops were exposed while in reality they would move along with the vehicle. So I created a move called a Screening Maneuver. It works like this:

Any unit moving along with a vehicle must first call for a screening maneuver. The vehicle moves and takes all its actions as normal. Once resolved the unit being screened moves along side it but cannot make any other actions. The opposing player then gets to make an additional move action on his next turn to balance out the added move action. It has worked ok but was looking for some feed back or if I missed this in the rules somewhere.

 There's certainly nothing in the rules covering this sort of movement.

 Might be cleaner if you just say that you can activate both at the same time and the infantry unit cannot shoot while screening move.  No need for the other side to get extra moves or anything then.

But getting to activate two units in a row can be a big tactical advantage, there should be some downside to it. Maybe the opponent can choose to activate two units in a row as well, but he's not limited to only moving.

Thanks for the suggestions. Im trying to keep things fair yet not slow down the game for this kind of stuff as well as keep to the basis of the rules. Let me know if you think of anything else.

Maybe roll for it like reactive fire? 

When a vehicle would move, a squad adjacent can roll for a hit to activate and move with the vehicle.  This counts as the squad's activation for this round.