How come the original Scarlet and Brown's bodies were still intact after the car exploded? Other episodes when Mysterons kill somebody in a car crash we see the dead person away from the wreckage intact.

If we saw Captain Scarlet reconstructed in the CG series we would've seen his dead body fade away as the replica is forming.

But Spectrum don't seem to treat him any differently, still talk to him like the original.

He's the Mysteron double but retaining the original's personality and mind, somehow. In the first episode we see Captain Scarlet's body on the ground by the feet of a shiny new Captain Scarlet, the Mysteron copy. Later, after the first attempt on the World President's life, there's a radio message that mentions the body of Captain Brown being found near scene of car crash, and Colonel White deduces that what happened to Brown may have happened to Scarlet, too.Colonel White, at the end of the first episode, also mentions that 'this' Captain Scarlet could be Spectrum's best weapon against the Mysterons. The implication seems to be that when Scarlet was replicated, his own personality and will were strong enough not to be subsumed and that the Mysteron control was broken when he fell from the Car Vue to his second 'death'. So the 'real' Scarlet died in the burning wreck of the SSC, but his 'spirit' lived on in a replica no longer under Mysteron control.
Whit sad old loser'd be thick enough to don thon get-up?