I've been going to San Luis Obispo so long I remember when this place really was a Firestone Tire store. OK, mark me down as a senior. Now Firestone is a Cal Poly student hangout with lots of good energy. There's both indoor seating (really noisy) and outdoor seating which is the best for most of the year in San Luis Obispo. Keep in mind it's considered a "walk-up" place. You pick up your own order and you bus your own dishes (baskets, really) so be ready. This is not a white-tablecloth place. The tri-tip sandwiches are legendary. I've been here a bunch of times and the tri-tip is always tender and properly cooked. Both the onion rings and fries are great too. I'm guessing the onion rings are the frozen ready-to-go-into-the fryer variety so stick to the fries. Get lots of napkins and some extra BBQ sauce; you're going to need both. The bar has a nice selection beer and (I presume) wine which you have to purchase separately from your meal (I haven't so far). Bring your appetite and be in the mood for some fun and energy. You won't be disappointed. If you're up the road in Cambria try the sister restaurant, the Main St. Grill.