So I finally had all 4 drives (red/stealth - blue/plasma - purple/void - green/emerald) and a Rare Sparrow. I chose to upgrade the Rare Sparrow with the Red/Stealth drive. It worked. My Rare Sparrow is now a Legendary Sparrow with the Red/Stealth Drive, BUT !! * * * THE GAME "USED" ALL 4 OF MY DRIVES * * * The other three drives from my inventory are ALSO gone, just like the Red/Stealth that I used. But my sparrow is not "QUAD DRIVE" - it's only the Red Boost, but *ALL 4* of my drives are gone. Without seeming snotty, you owe me nearly 100 Strange Coins, Bungie. Losing 3 Sparrow Drives (of all different color no less) is no laughing matter. That's more strange coins than doing MAX weekly strike 3x for almost a month on all characters. I am VERY DISPLEASED.