in my mind, it's become such a science that your regular guy can't relate anymore. the sport started by bringing what you had to the track, driving the wheels off it, and improving the car more than the other guys. sprinkle in a little cheating, and it was nothing that you or i couldn't do in our garage on the weekends.
now it's a science being dominated by the teams that have the most cars and therefore the most data. the cars are spec'd, although guys like knaus still find ways to cheat, and the tracks are smooth. the races have become dull and boring unless there are 43 cars crammed onto a half mile. also, each week, about 5-10 teams race 10 laps and pull off the track.
i still follow nascar because i'm a redneck at heart and i grew up watching with my dad, but i don't get excited much anymore. each sunday, if i think about it, i'll flip over to watch a little bit or pick up the last 30 laps. it's a crapshoot whether there will be racing going on or a leader ahead of the field by 9 seconds.