If you come to Guadalajara from the coast or the North you almost have to come through Tepic, Nayarit. Which means you will pass through Ixtlan, famous for the Carlos Castaneda title. Don't get too excited (much less jump bus and start asking for peyote) it's just one more drab little Mexican pueblucho. But hey, you can say you were there. By the way, the place everybody does go for peyote is Real de Catorce, which is a joke. You jump off the bus with your big flashing "GRINGO" light on and buy buttons from some Indians at the roadside stands, and guess what, the cops come over and take it (and you) away. Hell, you're better off just drinking.
Which works out, because your bus will also go through the little town of Tequila, which you've probably heard of in some connection or another. This is a funny place. After driving through all these dusty little towns, suddenly you hit Tequila, bright and prosperous and covered with fresh paint. Because every building in town (or at least visible from the highway) is painted with advertisements for noted Tequila distilleries. Even one of the smaller churches. My favorite slogan, "Orendain: The Family Tequila." This is where it originated of course, and most of the major brands keep a token plant here, although these days most tequila is made in big factories in Guadalajara. But you can stop off and buy it here. In fact you can get stuff not available elsewhere, like unlabeled plastic water bottles full of green, unaged, vintage-last-night tequila--white lightning with barbed wire implications. Guadalajara kids stop by and pick up a six pack of this stuff on their way down to the beach to court wrack and ruin. If your interest in tequila extends past the margarita level, you can learn a lot about its manufacture here, more colorful and complicated than normal booze. And you will pass through field after field of Weber's Blue Agave, from which tequila is made. (Sorry: it's not made of cactus, and does not contain worms. Deal with it.) The fields all have fences made of piled up rocks, since this is tough country and there isn't any wood around, just dirt and rocks. Much of this is explained (or at least befuddled) in the cool article, "Tequila: Medicine, Myth, or Menace"
By the way, if you go down to the coast the "other" way--to Manzanillo--you'll pass another nowhere little town called Autlan. No big deal except it's the birthplace of Carlos Santana. I always wave or toss a flower.