I do remember model kits were to be found everywhere: drug stores, dime stores, grocery stores. It seems the toy section of the grocery store mostly had cars models, though.
My Dad used to bring home auto dealer promo cars and I ended up with quite a collection of those. They were identical to the model kits, except were fully assembled. They were 1/32 scale and most often molded in one color, except for the chrome trim. Not too long ago, I looked up the price of some of the ones I had and about cried when I discovered those things are now worth a fortune!