Excuse My Dust.

A top race-car driver leaves the sport to get married and settle down, because his new wife doesn't want him to race anymore. However, not long afterwards his wife takes their infant son and leaves him to go to San Francisco. The husband gets word that his son is seriously ill in San Francisco, but he has no way to get there. Just in the nick of time, however, the racer's father-in-law just happens to have developed a new car for a cross-country race--to San Francisco!