30 sec ads on cable tv average $10K. Last night AMC was getting up to $400k per 30 seconds. They could bury their own barrels of cash in the desert.
Someone on the writing staff has a fixation on cars and using them as symbols. Walt's first car is the hideous Axtec, a metaphor for his boring meager life. Later he gets the new Charger, which symbolizes his success as a drug lord. He buys one for Junior and also wrecks one (it?) just for fun. Then when the Nazis steal most of his money, the Charger breaks down, and we never see it again. With only one barrel of cash, Walt is reduced to driving an old Chevy truck. Later when he turns badass again and goes to get revenge on a gang of killers, Gus Fring-style, he drives a Volvo, same as Fring.
As for the pimp car he was driving to see the nazis, I'm at a loss on that one. "No replacement for displacement" (?) Maybe he just needed a big car to hold the gun.
Jess begins the series driving the ridiculous ghetto hoopty car that represents his youthful ignorance and naivety. But when he shoots Tuco, his first violent crime, Hank shoots his car along with Tuco, and he has to leave it behind. He drives a station wagon after that, shortly before falling in love with Jane, whom he probably would have married and had kids with.
When Jesse escapes, driving as fast as he can, he does so in an El Camino, which is Spanish for "The Road."