Season 3 sees the Dukes head for Cedar City Fairgrounds in 'Carnival of Thrills'. I'm pretty sure this was filmed just north of New York Street, with the backs of buildings 1, 2 and 3 being visible under the sign. The tip of the church seems to be visible a little way above the '01' on the General's door. Most of the action in this episode takes place in or around the Hazzard Fair Grounds ('Fair Grounds' was 2 words on the poster). In real life this was filmed at Saugus Speedway on Soledad Canyon Road in Santa Clarita, CA. From what I can find online, this is now used for swap meets. It was also seen in 'Dukes Meet Cale Yarborough' and 'Hazzard Connection'. Here's a more recent picture, or you can explore it yourself on Google Maps. I'll finish this post with another mystery building. There's not a lot of background to go on here. When Rosco impounds the General it gets taken back to the Hazzard Impound Yard. Initially I assumed this was back in the corner near 'O'Connor Paint Supply' (where it had been in season 1), but I have a shot from 'Enos Strate to the Top' to post in the next day or so that shows this area has been changed. It could really be any corrugated building with a sign stuck on it. Here's another angle with what looks like a trailer behind Boss and Rosco (I love the look on Boss's face).