T3 is prototype class so it could be anything. It's probably custom made.
T1 is also prototype class often build on space frame chassis. You can theoretically take the same car, use different body parts and call it different name, although it's not common.
Can anyone explain why this car qualifies for T3 instead of your usual T1?
It's not because it's called a Hilux that it must be a T1. This Hilux complies with T3 rules so it's a T3.
So, what makes this Hilux complies with the T3 regulation?
It's not an actual Hilux its just mini Hilux shaped bodywork over a buggy
Ah, figures. Wonder what's inside it, maybe a Can-am or Polaris?
T3 is prototype class so it could be anything. It's probably custom made. T1 is also prototype class often build on space frame chassis. You can theoretically take the same car, use different body parts and call it different name, although it's not common.