There are several episodes of SUPERMAN from the 1950's with Kaisers. There is a fantastic chase scene in THE MAN WHO COULD READ MINDS involving a Kaiser in the lead (BAD GUYS) followed by Lois & Jimmy in her Nash Rambler convertible, followed by Clark and Perry in Perry's Packard convertible...bringing up the rear is inspector Henderson in a plain-clothes Nash 4-door sedan with a long whip antenna. All cars are 1953's. As for reaching through a radiator to get part of the engine, I've never seen that one, be it Kaiser or any other make. Usually he just grabbed the rear bumper or lifted up the back end.
However, it would be easy to shoot such a scene back then. Kaiser-Frazer's Southern California Division built two process cars for film and TV use. These were shells with interiors that came apart in sections depending on shot requirements. Water pumps, fans, other components could be set up to be "reached for" through the front opening.
KFOCI HANDBOOK VERSION 4.0 has a section on the process cars with pictures if anyone is interested.