Well, if Lekh can get inside the vehicle he could disable the drivers with his power, as they would only be ordinary humans. He could be inside the vehicle suppressing Racheli's ability to save herself, and at a pre-determined time unleash his power to disable the driver, perhaps at traffic lights? Then the ambush team can just pull up and take it over, without the risk of road block tactics or whatever method they were planning to use.

If Lekh is allowed to infiltrate the team in the back then he can definitely play a large part in any ambush. Not to mention his ability cuts out communication tech, preventing the people inside calling for backup. That may be the most important part he can play.