The listing, Mtn Dew 20 oz. bottle cap code Call of Duty MW3 has ended.
I don't play, but here's the details...
Specially marked packages will contain codes you can use to unlock double XP time in Modern Warfare 3's multiplayer. For example, a 20 ounce Mountain Dew bottle will give you 15 minutes of time, while a family size 17 ounce Doritos bag will give you 90 minutes of bonus XP time.
Entering both a Mountain Dew and Doritos code together will earn an additional "Power Bonus," or 15 minutes of extra XP time. Here's a sample listing of the products you can get, and the time you'll receive:
Mtn Dew® 20 oz. bottle = 15 minutes
Mtn Dew® 12-pack = 45 minutes
Mtn Dew® 20-pack from Walmart = 90 minutes
32 oz. or 44 oz. Mtn Dew® fountain cups = 15 minutes
2.125 oz. or 2.875 oz. Doritos® bags = 15 minutes
11.5 oz. Doritos® bag = 45 minutes
Family Size 17 oz. Doritos® bag from Walmart = 90 minutes
Power Bonus (any Mtn Dew® and Doritos® combination) = 15 minutes
The promo will let you accumulate up to 24 hours of double XP time, which will give you a valuable leg up on your journey towards Prestige ranking. In addition, every time you enter a code, you'll receive a "Combat Card," which features additional special content, such as new weapons, characters, maps, perks, and strike packages. (Copied from the promo site)
Thanks and good luck!