If you can catch any of the tool trucks while you're driving or before you leave (Mac, Snap-On, etc.) they have locking lug nut removal kits. Might be kinda pricey I think less than $100 but at least you know you can get them off if you need to.

Kinda related to the thread, can I see what kind of MB wheels did you get? Do you have pics or a link? I was looking at some of them since they are priced nicely.

 

2 ways to remove locking lugs without a key that I have used.

- grind a groove in the outside of the nut with a die grinder, dremel, or hand file and then use a chissle to knock it loose.

- Buy some cheap sockets and weld them to the locking nuts.