Whilst looking for something else I discover I have a BT-7 tank model. No idea who's as it's unboxed but it appears to be in "wargames scale". So maybe a racing tank as they were fast tanks after all 
Tank racing sounds an interesting sport. Perhaps a military biathlon event as in the winter Olympics :-
"Biathlon is a Winter Olympic Sport which combines cross country skiing with precision target shooting." Race your competitors round a cross country course with tank target shooting on the way.
Cromwell, or Tank, Cruiser, Mk VIII, (A27M), was good for 40 mph and could even leap across wide ditches according to Wikipedia
Cromwell was the fastest British tank to serve in the Second World War, with a top speed of 40 mph (64 km/h). This speed was extremely beneficial in both attack and defence, outmanoeuvring opponents. At least one case is known of vehicle commanders using the vehicle's fast speed to jump large gaps. In The Netherlands, a troop of three Cromwells was able to leap a 20 ft wide canal when surprised by enemy forces Then there is the Scimitar/Scorpion / Sabre family to consider.