Well, this situation has certainly brought up some game mechanics that need to be addressed. There's a lot here as an effort on my part to avoid repeated questions, but it's our first Chase, so we need to address mechanics.
To clarify available actions/maneuvers for the ECUL (and most non-combat vehicles in general) I've updated the Group Finances and Assets to make it clear what characters can/can't do from their positions in the ECUL (all of you should take a look and see your options); please refer to this before posting any Maneuvers or Actions.
Drama, as the Pilot, I'll need you to give some kind of direction as we move forward into structured time, using Maneuvers/Actions via the F&D rules starting on p. 238, or there's two really good links in the Library, under Links to Useful Resources and Reference Sheets Without your direction as the Pilot, I simply had Lexi perform the 'Drive' Maneuver..
Taking a look through the rear view and side view image screens, Tajanna gets a good enough look to discern that the silver landspeeder is a 4-seater, doesn't seem to have any upgrades, and appears to be occupied by a pilot and one passenger.
Tension builds as you wait for the traffic signal, which, like every traffic signal, doesn't want to give you the go ahead. Left hand on the wheel, right hand on the throttle, Lexi waits, like pod-racer at the starting line.
The traffic crossing the intersection in front of you slows down, then stops. The signal ahead changes.
Go.
Traffic sluggishly starts forward, and, despite her urge to punch the throttle, Lexi does so in kind. Most of the vehicles continue on the path forward, some turning to the left or right. A keen eye on the traffic, Tajanna notices some vehicles ahead, separating, the beginnings of an opening to exploit. Lexi nods, playing it cool as if she was none the wiser about the Silver Speeder tail behind you, then abruptly makes her move, aggressively separating from the pack as she pushes the throttle forward.
The ECUL is now at Speed 1. We'll be using the Chase Rules (F&D p.247) and Competitive checks.
The base difficulty for these checks is going to be the vehicle's speed, upgraded by half the vehicle silhouette. So, for this turn, at Speed 1, the base Difficulty for the check you're making is going to be 1 Red + 1 Setback for fairly dense traffic at this speed. Remember, you have a Boost from Tajanna's Assist, and to my knowledge Enhance: Agility is running. The Silver Speeder is at Short Range.
Additionally, Lexi, you have three choices here as you make your first move through traffic, starting from the center lane:
Right or Left turn: Less time to make the turn (as opposed to going forward) requires a narrower squeeze through space, adding 1 Setback to your roll. Less traffic after either turn, as most of the traffic surrounding you is going forward.
Straight: More time to make your opening move, allowing space to open up a little more, so no additional Setback beyond the base difficulty. More traffic flow around you keeping straight.
Traffic is both ways, 3 lanes on each side (6 total from one side of the street to the other). Sidewalks aren't wide enough for anything bigger than a speeder bike.
Scan the Enemy for Tajanna is going to be a regular check via using her senses, simply trying to get a good look at the vehicle, using the side/rear image screens (SW equivalent of side/rear view mirrors); the ECUL doesn't have any such advanced scanning systems like a starship would for detecting weapon systems, etc.
Also, just like on a starship, the only time Tajanna could access true 'Pilot Only' actions is if the pilot ceded control; until that point, the actions available are of the Co-Pilot position nature, as described for the Spear of Akrulta on it's own thread.
In addition to the narrative points, Tajanna's Scan Enemy discerns that the Silver Speeder, being a stock civilian type, has a Hull Threshold of 4, and a System Strain Threshold of 5.