At a petrol station in Zuidlaren you quickly scrape your windscreen free of ice and get in. The roof, rear window and number plate are still covered in a layer of snow. May you drive off?
No, I first also clear the roof, rear window and number plate
Yes, the windscreen is the only thing that counts for sufficient sight
Explanation
Wrong — trap: one window treated as the whole vehicle. You clear windows, lights, mirrors, roof AND number plates (Book p.192).