NASCAR Racing: Starting grid, starting grid, richard petty

Question
Why do they have 43 cars in the starting line-up, not 42 or 44?

Answer
Over the years the starting grid evolved to 42 cars at the large tracks and 36 at the short tracks (mostly through the 70's and early 80's). It eventually became 42 at every track as more able teams tried qualifying.

The 43rd position (or the Richard Petty position) came about in the late 80's as the "King" was starting his decline. For the first time in his waning career(I believe it was at Richmond) he failed to qualify and had to pack up his team and head home. The uproar and the loss of ticket sales (back then every race was NOT a sell-out and many fans stayed home if their driver wasn't driving) made NASCAR pass the "Past Champions" provisional that was used to get any past WC champion into a race if he had not made the field. This eventually became the 43rd starting spot.