Totally bogus storyline about radiation contamination. The main bad guy (Underwood) absorbed a fatal dose of radiation in the lab accident. This could happen. But, he contaminates everyone and everything he meets or touches. Radiation poisoning is not passed on like a common cold and does not leave a trail of gamma rays. A radioactive source, a piece of material will only do this. Underwood did not have numerous radioactive sources that he was dropping wherever he went.
The 1963 Ford Galaxie Ambo (blue/white) was shown in the epilog.
Also note that Underwood had a protective suit on in the lab when the explosion occured. The suit was not damaged so it is highly doubtful that Underwood would be carrying any radioactive sources on his person.