Season 1, episode 6.
Original air date: 5 August 1957.
A young couple stop at the Good Eats Casino Grill . While inside their car is stolen and used to stage a hit and run. Believing them to be innocent, Diamond arranges a hit with hinself as the target but all does not go according to D`s plan.
Cast: David Janssen (Richard Diamond), Regis Toomey (Lt. McGough), Grant Richards (Joe Wells), Tommy Cook (Baron), Nick Dennis (Chico Burns), Bill Erwin (Sgt. Riker), Dawn Richard (Laurie Gates), Bud slater (Bob Winters) and Dennis Moore (Motorcycle Cop).
From IMDB.

Richard Diamond is one of the best PI shows ever made. This one Hit An Run shows how good Richard Diamond was. David Janssen did a great job. An the acting was the best. So give it a look.

Original Air Date:
5 August 1957 (Season 1, Episode 6)

The method of murder here is very, very brutal. These men don't use guns, knives, or poisons but they do push tied up people in front of speeding cars. The impatience of the one man is remarkable. Dig the wide whitewall tires and hardtop cars with those fins.