@ciane I think your end car observation deck looks great. Nice job.
@everyone - I decided to redo my parlour cars in the appropriate base car thinking that, while I could redo the wallpaper easily enough, I wasn't so sure about placing the signage and thinking it would be better to use the other little improvements. (By the way, I'm just amazed at how wonderful the signage looks on all of them!) Anyway, while working on them, I sent in a sim and discovered he couldn't go up *any* of stairs to the entry doors. I had to turn the bike racks around again, and then they were fine. They weren't causing me any problems before (except one thing I tried and then changed), so that's no big deal for me. Just thought I'd let you all know before you get too far with things.
Edited to add: Has anyone tried a 3-wide window on a front car that they liked? I can't remember if that came up. Cygnus is a front car, and I've put the kitchen at the front on my second try at it (never mind why it didn't work out that way the first time lol). I have the bistro oven on that wall, and the only thing I found I liked above it is the BauHas Intrinsic Window:
https://store.thesims3.com/productDetail.html?productId=OFB-SIM3:19623&scategoryId=11573 . Problem is, from the outside it looks like a horse trailer to me.