Judging from trial and error within my own sub-account (my son's) yesterday, as long as you haven't sent any cars or car tickets from your account today you are good. You can send one and one only per day - even if you perform the b-day exploit or quit before the 2nd OK glitch.
In any case, go ahead and Friend me on PSN. I only do 1 trade a day. Period. What about you , are you "clean" today?