I'd invest in a detailed clean from a profeesional (including a claying plus polishing), then you could top up the wax with Collinite 915 (cots about £23) and water just doesn't stick to the paint work after this has been applied. Subsequent cleaning jobs will be very easy and quick as most of the muck comes of with a rinse of a pressure washer.
If your using buckets fella I'd try and get access to a hose at least as these cars are truly massive.
