The UniSA prototype car used 14x5J 45 alloy wheels from a Suzuki Cappuccino, with 165/65R14 Michelin Energy tyres (the last three in Australia). The combined mass of a wheel and tyre was 10.6 kg. The Team Trev version used the same size front wheels, from a Can-Am Spyder, with the same tyres that were used to drive from Darwin to Adelaide; we could not find a low-energy car tyre for the rear scooter rim.
Trev does not need wheels and tyres designed for 1--2 tonne vehicles.
Continental make a small EV tyre with low rolling resistance. There will be others.
Trev did not carry a spare tyre from Darwin to Adelaide. Team Trev carried a spare rear motorcycle tyre around the world with them, but did not use it. Carry a can of tyre repair goo instead.
The front suspension is unequal length wishbones. The original design did not allow enough movement. Team Trev modified the design to allow longer wishbones, modified from a Can-Am Spyder.
The UniSA prototype used a single-arm swing arm with the motor mounted to the body and a two-stage belt drive with a reduction gear on the swing-arm pivot.
Team Trev replaced this with the rear end from a Vectrix electric scooter, which was simpler but had greater unsprung mass, and a smaller rear wheel for which low-resistance tyres were unobtainable.
The ideal rear suspension would be a swing-arm unit completely external to the vehicle, with the motor mounted near the pivot.