Near the end of the movie, Bronson’s assistant double crosses him and kills him. Then the movie ends showing the assistant entering his car where he finds a note left by Bronson (or was it a cassete?) essentially saying “If you can read this it means you killed me”. Then the car goes boom.
Wise decision, in my opinion. The remake goes overboard on some of the action. The final scene in particular was far better in the original, both physically plausible and dramatically engaging, neither of which I can say for the remake.