This model from Tamiya does not require you do do any assembly before driving it. The product's scale is 1:14.
From Amazon
Tamiya 300056323 radio controlled Scania R620 Highline tractor truck model kit - 3 axle - 1:14 scale
eModels
Tamiya 1/14 RC Scania R620 Highline # 56323 - Radio Controlled