Hi Malckuss. I answered this over at DriveThru but I'll follow up here. Vehicle upgrades refer to vehicle armor and handling increase found on page 50. And as you also mentioned, vehicles can be fitted as a drone with a control brick (pg 33) and can likewise take intelligence upgrade. It's not explicitly stated in the rules yet, but a vehicle could easily have hard points appropriate for its size and be outfitted with drone mods like weapons and sensors.
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Yes exactly. I'd suggest 4 hard points for motorcycles (medium), 5 hard points for sedans (large), and 6 hard points for SUVs and small trucks (extra large?). That tracks with the existing capacity in place for drones based on size (pg 33). Also, there could be some expense for "installing" custom hard points on a vehicle...I think 500 c. per point is reasonable.