Retro-future-cities should look something like this:
My buildings are too boxy for that. A complete overhaul would blow the ability to pack it all into one tidy box right out of the aetherium. What to do, what to do? We're gonna need the right paint scheme and some baubles on those buildings to retro-fy them. There's a great example of the sort of styling that I'm looking for over at Lead Doesn't Bleed (take a look). All those spires and pointy bits will prevent this terrain from packing into its box, but we can still mimic the overall aesthetic with the right baubles and paints.
We can also use architectural features like bridges to add flavor.
That's a nice sweeping bridge with plenty of potential for some 1950's style sci-fi crystals or some such. This bridge also includes a clever solution to the stability problem. Here's a close-up:
Next up, uhhh...I better get cracking.