what is the red thing behind the motor?
That's the battery connector.
Mods I have done:
Alloy shocks & caps (gold colour)
RPM spring retainers on the shocks
Traxxas rod ends for the lower shock ends
purple hex hub clamps (HPI part # 86300)
Proline Snake Eyes tyres all round.
HPI graphite top deck.
Hellfire fuel filter
RPM long rod ends for all turn buckles
Futaba 9451 servo for steering
Water ballons for shock boots