The Feicui Aircar Hovercraft, the Avanti Luxury Sedan, the Heavy Transport and the Typhoon Ground Car, however, haven't managed to add up. They either have to be smallet than their range and fuell mass would permit, have more cargo mass than listed, or have some other piece of equipment or chassis mod I haven't been able to discern:
The Feicui Aircar Hovercraft must mass somewhere between 2703 and 2756 kg; at 2703 kg, 107 kg are still unaccounted for. I say 2750 kg is a nice, round number, which leaves it 125 kg underweight. This goes up to 400 kg (!) if we make it Ultralight like its brethren. The difference between calculated and list price could be explained by general Avanti greed and to foster exclusiveness, but added to the missing mass... one could fit a substantial infantry support weapon and not go overbudget.
FEICUI AIRCAR HOVERCRAFT:
Small Support Vehicle
Total Mass: 2750 kg
Rating: D/X-E-E/B
Chassis: Hover (Ultralight), TL D [275kg, 1289.0625 C-Bills]
Engine: Fuel Cell Engine, Speed 13/20, TL D [1190 kg, 10412.5 C-Bills]
Fuel: Hydrogen, 302 km Operational Range, TL D [54 kg, 0 C-Bills]
Seats: 7 Standard [525 kg, 700 C-Bills]
Armor: 3 Front, 1 Sides, 1 Aft, BAR 3, TL D [114 kg, 750 C-Bills]
Cargo: 192 kg [192 kg, 0 C-Bills]
Unspecified: 400 kg [400 kg, ? C-Bills]
Total: 2750 kg, 13875 C-Bills (140000 C-Bills list price)
Cruise Speed: 75.6 km/h
Flank Speed: 118.8 km/h
Notes: Uses Ultralight chassis and controls modification, 1 crew seat/standard (75 kg), 6 passenger seats/standard (450 kg), and 192 kg of cargo space.
The Avanti Luxury Sedan must mass between 2383 and 2497 kg, but to mount the amount of armor listed it must mass at least 2500 kg. Even at the minimum weight, 113 kg are unaccounted for. I pick a mass of 2400 kg and add the missing 146 kg to unspecified luxury items. The difference in the costs is huge.
AVANTI LUXURY SEDAN:
Small Support Vehicle
Total Mass: 2400 kg
Rating: C/X-E-D/B
Chassis: Wheeled, TL C [332kg, 830 C-Bills]
Engine: Internal Combustion Engine, Speed 8/12, TL C [816 kg, 4080 C-Bills]
Fuel: Petrochemicals, 259 km Operational Range, TL C [54 kg, 0 C-Bills]
Seats: 8 Standard [600 kg, 800 C-Bills]
Armor: 3 Front, 2 Sides, 2 Aft, BAR 3, TL C [114 kg, 750 C-Bills]
Cargo: 292 kg [292 kg, 0 C-Bills]
Unspecified: 146 kg [146 kg, ? C-Bills]
Total: 2400 kg, 6589 C-Bills (70000 C-Bills list price)
Cruise Speed: 86.4 km/h
Flank Speed: 129.6 km/h
Notes: Has 1 crew seat/standard (75 kg), 6 passenger seats/standard (450 kg), and 292 kg of cargo space.
The Heavy Transport is basically a 20 ton truck with a bit more than 10% of its mass devoted to cargo. Even though as a medium SV it should have a crew of two, it's listed as having a crew of one; both seats should have been free but ended up having been paid for. Even then, the build is 0.5 tons light. The costs, at least, are close to each other.
TRANSPORT, HEAVY:
Medium Support Vehicle
Total Mass: 20 tons
Rating: C/B-B-B/C
Chassis: Wheeled, TL C [3 t, 7500 C-Bills]
Engine: Internal Combustion Engine, Speed 6/9, TL C [12 t, 60000 C-Bills]
Fuel: Petrochemical, 833 km Operational Range, TL C [1 t, 0 C-Bills]
Seats: 2 Standard [0.15 t, 200 C-Bills]
Armor: 6 Front, 5 Sides, 5 Aft, BAR 5, TL C [1 t, 4200 C-Bills]
Cargo: 2350 kg [2.35 t, 0 C-Bills]
Unspecified: 500 kg [0.5 t, ? C-Bills]
Total: 20 t, 79090 C-Bills (90000 C-Bills list price)
Cruise Speed: 64.8 km/h
Flank Speed: 97.2 km/h
Notes: Has 1 crew seat/standard (75 kg), 1 passenger seat/standard (75 kg), and 2350 kg of cargo space.
A lightweight, the Typhoon must mass between 901 and 1000 kg. Even at the smallest size, and making it convertible AND a tractor, it's still light by 7 kg. Using anything less than a full ton would necessitate dropping a point of armor, though. The difference in cost is staggering.
TYPHOON GROUND CAR:
Small Support Vehicle
Total Mass: 1000 kg
Rating: C/D-D-D/B
Chassis: Wheeled, TL C [138kg, 345 C-Bills]
Engine: Internal Combustion Engine, Speed 8/12, TL C [340 kg, 1700 C-Bills]
Fuel: Petrochemical, 294 km Operational Range, TL C [10 kg, 0 C-Bills]
Seats: 4 Standard [300 kg, 400 C-Bills]
Armor: 3 Front, 1 Sides, 1 Aft, BAR 2, TL C [96 kg, 300 C-Bills]
Cargo: 16 kg [16 kg, 0 C-Bills]
Unspecified: 100 kg [100 kg, ? C-Bills]
Total: 1000 kg, 2759 C-Bills (35000 C-Bills list price)
Cruise Speed: 86.4 km/h
Flank Speed: 129.6 km/h
Notes: Has 1 crew seat/standard (75 kg), 3 passenger seats/standard (325 kg), and 16 kg of cargo space.
Finally, a possible version of the Speeder; here, rather than a bike, it's more like a racing car:
SPEEDER:
Small Support Vehicle
Total Mass: 1350 kg
Rating: E/C-E-D/B
Chassis: Wheeled (Ultralight), TL E [69kg, 388.125 C-Bills]
Engine: Fusion Engine, Speed 13/20, TL E [1023 kg, 15345 C-Bills]
Fuel: Not Applicable [0 kg, 0 C-Bills]
Seats: 1 Standard [75 kg, 100 C-Bills]
Armor: 3 Front, 1 Sides, 1 Aft, BAR 5, TL E [168 kg, 1800 C-Bills]
Cargo: 15 kg [15 kg, 0 C-Bills]
Total: 1350 kg, 17753 C-Bills (23000 C-Bills list price)
Cruise Speed: 216 km/h
Flank Speed: 324 km/h
Notes: Uses Ultralight chassis and controls modification, 1 crew seat/standard (75 kg), and 15 kg of cargo space.
Edit: Separated the missing mass into "unspecified" component. The Avanti is still underweight for its armor.