Another vote for Zaino here. I have to park outside (offstreet at least, thankfully). I can't do waxing 1 day a month, so the 6 months a few layers of Zaino will last does the trick for me.
You can always re-apply Zaino CS midway through your 6-month cycle after a wash as well. Keeps the other stuff on.
'11 550i, but it's too big for me
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