I have a 5 month old border collie, Molly, who constantly lunges at cars, tractors, in fact any vehicle that passes.
We live in the countryside where most roads are very quiet and have no pavements, so walking involves getting onto the grass verge whenever a car comes past. Molly has learned very well to get onto the verge but will then crouch till the vehicle has passed then lunges to chase after it barking like crazy. I usually walk her for a couple of hourly walks every day and she spends the whole time alert and listening for traffic. She becomes totally fixated whenever she hears an engine. We often play frizbie in empty field and she will drop this to chase along the fence next to the road if a car passes.
I have tried desensitizing her by taking her into town and sitting at busy junctions watching the traffic go passed and she eventually lies down and ignores the the cars totally but reverts back as soon as I walk her at home.
I have also tried 'sit/stay' to get her attention before the car comes into sight but this doesn't last once she sees the car and it's impossible to distract her. Help:confused: