I share your gf's thirst for Mountain Dew. I happen to live within a couple miles from one of those online places, so it's not difficult to get there in person. I can't vouch for London, but I think you might be stuck with online ordering.
Pepsi manufactures Mountian Dew and has its Europe distribution in central Europe.
Pepsi in Central EuropeRoad trip to Slovakia, anyone?
My brother who lives in Germany can pick up Mountains of Dew, but I don't know if it's strictly sold in the PX where he is.
I think a letter-writing campaign is in order!
Executive Management Headquarters PepsiAmericas
4000 Dain Rauscher Plaza
60 South Sixth Street
Minneapolis, MN 55402
info@pepsiamericas.com
I'm not extremely hopeful, however. Somewhere along the line I did hear that the caffeine content of Dew is what's holding it back from coming in this country under general pepsi distribution. (I mean, afterall, we do have Pepsi here.) although, I could find nothing in their web site to indicate any reason, just a vow from management that their goal is to increase sales in Europe.
I think I have an idea how.
Can't advise on the Cheetos. :-/
Will def check out Cafe Pacifico!