I understand what you're saying but can't understand why that should be the case
No idea but its worked for me for my last 3 cars lol.
Same as the parking on a street not your drive.... Doesnt really make sense, Its something along the lines of.... if someone sees your car, wants it, they know which house to break into for the keys...
if it's on the street it could belong to anyone.
But your right on the +1month thing. Makes no sense but has never not worked for me. I insured a buddy on a Mercedes GL, done the 1month trick and it came down by nearly £200. Granted that is a 70k motor, but it works, try it - every little is a bonus for youngsters on rip-off insurance.