[MetroMPG]

Shifting technique notwithstanding (I'm surprised you assume all cars will behave the same way yours will, Frank), it could be a case of the alternator working harder on start-up due to 12v drain during the coasting portion. If the belt's old or a little loose, it may squeal under those conditions but not in "normal" use.

Regardless, not being sure whether its tire squeal or belt squeal would have me wondering whether this technique may be outside your comfort zone.