[MetroMPG]

I'd take the entire roof rack assembly off, if the bolts are external (some are horrible to remove from the inside, requiring you to get under the headliner).

Removing the crossbars is a start, but we rarely drive in no wind or in a true head/tail wind, so the impact of the side portion of the racks is bigger than their small frontal area might suggest viewed from head-on. In a crosswind, their effective frontal area is significant.