This is what I was thinking. Rather than modifying the vehicle just have the values you want as a Police Model of that vehicle. Think the Police Interceptors that were built on the Ford Crown Victoria model.
Silhouette: 3 Speed: 1 Handling: 0
HT: 12(you had 10 and added the Hull Reinforcement +2 more) ST: 8 Defense: 0/0 Armor: 1 (you had 0, but maybe 2)
Hull Type: Speeder Truck
Categories: Land Vehicle
Maximum Altitude: 8 Meters
Sensor: Medium (you had Short but added Upgraded Comms)
Crew: 1 Pilot, 1 Transport Guard (You had just 1 Pilot)
Encumbrance Capacity: 135
Passengers: 11
Price: 25,000 - 30,000ish (upped base price from 7,000)
Rarity: 6-8 (Higher Rarity for Law Enforcement Vehicle)
Customization Hardpoints: 3
Attachments: None (yet)
To which they can have the SWAT version and the paddy wagon version and command center version.