It would be rewarding get every bonus on challenge at once, at least if you beat all level. Maybe achieving the past one you are not able to get again. Something like that.
@Eklipsed I've got same issue, but I solve it by pressing both up and left or right.
In any case in some races the car is facing opposite way like tracks 2 and 3 of "sane" circuit.
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 "Bloody Harry"){kind=icon}
 "Sky Quest"){kind=icon}
 "Big Time Racing"){kind=icon}
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