Plot hole: Ice Cube's cameo is really neat for the fans of the series, but does not make a lick of sense. Brushing aside the fact that the fangirl knows who he is when in theory his involvement in XXX 2 was never officially sanctioned and he gets no mention, presidential pardon or anything in his own movie, the fact that dialing 9 he just shows up in the space of minutes in Detroit with no reason for him to be there is nothing short of supernatural.
Plot hole: A plot twists occurs around midway through the movie; the Pandora's Box that was stolen at the beginning of the movie was not the 'real' one but just a prototype which, Becky Clearidge says, "Only ever had the ability to control one satellite." Literally a couple minutes later, Serena says they found the Pandora's Box (the one they did not know was just a prototype) because it "needs to keep reconnecting itself because the satellites orbit." First of all; they found the prototype, which already crashed the one satellite it could control...so what was it reconnecting to? Second; they know nothing of this actual model, but are able instantly to track it down with this 'newfound' knowledge, which means that A) the box is ridiculously easy to track down for anybody B) they should have spotted this second signal already when they tracked down the prototype. (00:59:20 - 01:01:40)
Plot hole: Donnie Yen rides away on the bike while XXX is still fighting baddies on foot, and when he grabs a bike he fights some more off with one wheeled acrobatics. So Donnie should have a huge head start, and inside the jungle of the hideout he knows and Xander does not. Still, with no explanation a couple scenes later they are side-to-side, Xander just happens to have miraculously caught up with him. (00:55:30)