In the narration at the end of the Season 4 episode "The Competition" (where Chad first appeared), it is stated that the family never saw Chad again.
When John-Boy buys gas, Jason tells him, "That'll be 60 cents, cash on the barrelhead." "Cash on the barrelhead" is an American idiom meaning immediate payment up front before any goods or services are received. When you are expected to put cash on the barrelhead you are expected to pay without delay, with no credit allowed. According to lexicographer Charles Earl Funk, the idiom may have arisen in the days when barrels were used as tables in bars or saloons and patrons were expected to pay for their drinks immediately as they ordered them, literally placing cash on the heads of the barrels.
About halfway through this episode, there is a view of the entrance to Ike Godsey's store. There is a sign on one of the doors that reads in large letters "NRA". However, the sign is not referring to the National Rifle Association. It is in fact referring to the National Recovery Administration. This was a government agency existing at the time designed to help businesses prosper in the wake of the Depression. It is logical that any business in this era might well display such a sign.
The narration about Chad has been removed at the end of the episode S4 E8.