The combo is: VCX-100 + TLT + FCS + Luke (or Gunner). Say you're shooting at a target in arc at range 2-3. Attack with the TLT and try to hit once and miss once (if necessary you can use the target lock from FCS on your second TLT shot to try to make it miss). Then (thanks to the miss and Luke) make a 4-dice primary attack with TL + Luke.
Per the new FAQ, I believe this works if you miss either TLT shot, not just the second one. If you miss the first TLT shot you now have two triggered events from the same trigger ("perform another attack against the same target using this weapon" and "perform a primary weapon attack"), and you can resolve the second TLT attack first (and maybe hit) and then resolve the primary attack.
A normal VCX on its engagement round would get 3 hits with its primary (4 dice with either TL or focus). With this combo, you can get 3.4 hits on your primary plus 1 TLT damage (or against aces, two attacks to strip tokens) and it doesn't even take your action, so you can also evade and stay healthier.
It is quite expensive, though. 50 points for a Lothal Rebel with TLT + FCS + Luke. You could even run two and put Gunner + Han on the second one...