The red Chevelle started as a '68 or '69 and alternates between that and a '70 in the initial chase scene.
When Kyle and Jason are playing in the "dungeon" with Angelo and all three are on the sofa with Kyle on top of Angleo as Angelo's bodyguard comes into the room, you can see Kyle's blue underwear (at 56:03 and 56:08 to 56:10 in 99 minute version). Later, when Lenny pulls Kyle out of the trunk (boot) of the car at the airport, he has white underwear (at 01:12:48 to 01:12:50).