I am not a fan of electric handbrakes as I had one deploy at 50mph in a job Disco, fortunately without incident. Another in a brand new Vauxhall Insignia which I left parked on a steep driveway while doing a call on, the handbrake let go and the car proceeded down the drive backwards across the lane into a tree causing considerable damage, fortunately the Boss was with me and witnessed it was not my fault. We had several similar incidents with those cars.