If its running down the side of the tank where the fuel pump is (drivers side), I'd say its a dodgy tank seal around the fuel pump assembly, causing the fuel to slosh out around corners. If so, then its a cheap and easy fix

If I were you, I'd try your dealer warranty. Tell them its a dangerous problem and they should fix it...play the "unroadworthy, fire hazard" card, and they may listen to you.