Protagonist comes across USD2 million in criminals' money and keeps it. Takes it home to his trailer in a desert trailer park. Is pursued by a killer and gangs, there is a nattily dressed cowboy put on the case by businessmen in an office in Dallas, cars are burnt out in the desert, cops stop cars on lonely highways, scummy motels, wife killed, shootout, and so on.
Oh wait, that's Charley Varrick a 1973 Walter Matthau film.