OOC:
Sorry about the delay, everyone. I'm going to detail Dell's thoughts here chronologically as events unfolded, we'll see where we end up. Just let me know/roll for me if you need any additional dice thrown.
As Dell first gains the driver's seat, he initially swings the Speed E. in a wide arc toward the building entrance, paying little mind to any parking lot signage or right of way. He's aiming to see if they can catch any sight of the others to extract them. (With the general approach that if he had an unobstructed path to them, he'd make a beeline and then slow down long enough to pick them up before heading out, otherwise he'd complete the circle and head back out to the highway, ditch the Speed E as soon as possible, and go to ground with the good doctor to meet up with the others when it seemed safe).
As the guard stalks forward, he's of the same mind as Ava, and even as she calls out a warning he's already trying to shimmy the vehicle aggressively from side to side in an attempt to knock the man off his feet in hopes they might be able to simply shove him out the back.
The stunner striking his headrest makes it obvious that plan won't be successful. As Ava grapples with the guard to neutralize him, Dell keeps one hand on the wheel and attempts to use the other to rip off the guard's helmet (if it proves detachable) and attempt to break it against their opponent's face. If doesn't come free with a good tug, he'll aim to smash the helmet cam into the side wall of the vehicle along with its occupant's head until neither one appears to remain functional. All while trying to keep one to one half an eye on the road.