Factual error: The crew sets off explosives so the armored truck will fall through the street into the subway tunnel. In reality, the subway tunnels underneath Hollywood Blvd are about 6 stories underground. That means the truck would have to fall through approximately 80 feet of concrete, soil, rock and more concrete to fall into the tunnel.
Factual error: In the scene where Charlie is introducing the gang to Stella, the Napster arrives on a yellow Ducati motorcycle. All Ducatis are twin cylinder machines which have a distinctive throbbing exhaust note. The sound used is from a higher revving four cylinder machine, definitely not the bike being ridden. The same is true of the motorcycle chase scenes - they are BMWs, opposed twin configuration not producing the 4-cylinder engine noise, which must be overdubbed.
Factual error: In the Mini Cooper subway scene, the cars are first seen outside of the Hollywood/Highland red line station. However, when they jump in front of the metro rail line, it is the blue line they are jumping in front of and not the red line. The only red line station that meets up with the blue line is the 7th Street/Metro station, not the Hollywood/Highland station.