I haven't played my ds online since I got the wireless connection either, but I own both 42 all-time classics and Mario Kart (really bad at this one though)
Don't know where mario kart is for the time being, but I'll make sure to check my 42 all-time classics friends code next time I'm near my ds (if I figure out how to find it..
).
Edit: I found my friends code! It's 1375 4883 6067
I've registered you.