In the mission "Holland Nights".If you watch the cutscene,you will hear francis say "the pay is good,2gs" then niko says "you mean 5?"
this could be a refrence to bully(another game by rockstar) where in a mission called "save algie" the protoganist and algie talk,algie says"I'll pay you!i.i'l pay you 2 bucks!" then the protoganist says "2 bucks? are you crazy? make it five" algie replies "no..2bucks?" the protoganist "great,five bucks,lets go buddy"
anyone found this? hmmm?