Smartuki has Reverse gear... This gearbox is why that smartuki kit is expensive - most of the cost lies in the quaife differential and reverse gear lets say its a bit over 4k alone... the gearbox is the same that is used in the Radical SR3
(VVVVVV.radicalmotorsport.com/range/sr3/sr3.php)
I will post some pic next month...