just run some soft compound offroad tyres till they are bald
I got the perfect set of bald schumacher minipins that are good fun onroad and generate plentty of grip
Or you could try these 1/10th scale buggy street tyres there the perfect fit:
http://modelsport.co.uk/?CallFunctio...n&ItemID=29892
http://modelsport.co.uk/?CallFunctio...n&ItemID=29893