LIFE ON TITAN
Above is the well-known Downtown Moths. It's located Downtown on a line between Police HQ and the entrance to the Highrise Tunnel. It's part of a complex with a lot of businesses with "Downtown" in their names like Downtown Chemicals and Downtown Components.
This is where you go to buy a better Moth. They keep a regular stock of Hawks, Neo-Tigers, and Moon Moths. By special trading, you can get them to build you a Death's Head, Police Moth, or Swallow. This is some especially satisfying trading.
Downtown Moths regularly buys Sheet Metal, Plastics, CompComp, MachParts, Cells #1-3, plain Lasers, Ore, and Food. You might not want to sell them Food if you're trading for a special Moth. This conserves their money. The key to getting a specific Moth built is in what Cell you trade them. Cell #3s encourage Death's Head and Police Moth production. The Swallow requires Cell #1.
Downtown Components is right beside Downtown Moths. The image above is what you'd see if you turned left from approaching Downtown Moths' hangar door.
Downtown Components is a great place to buy all sorts of Moth accessories like Cells, Chaff, and Drones. If you can find and sell them some Fusion Parts and stock them on everything else they need, they'll build you a Fusion Cell.
Downtown Components regularly buy Chemicals, Pure Water, Sheet Metal, ExMetal, Plastics, Gems, and Food. They'll buy Fusion Parts as stated above for $2000/per unit. A standard run of 3 Fusion Parts, along with the other goods, will encourage them to produce 2 Fusion Cells.
Software Shack #1
Software Shack #1 is located in the Downtown Crater right across from the famous Downtown 05 (a good hangar to own). The easiest way to find it is to start at Psycho Bob's 1, target Trade Central, and look down and to the left. It's in a row of four hangars and the hangar door faces Downtown 05 (to your left with this approach). They buy nothing, but sell software for your Moth.
Software Shack #2
Software Shack #2 is located in the Downtown Crater at the southwest corner of the Trade Central complex. It's easiest to find by targeting Trade Central, facing Trade Central's hangar door, and then flying down and to the left. The hangar door faces outward from the complex. They buy nothing, but sell software for your Moth.
Software Refinery is located in the Riverside Crater behind the Ore House. Find it by entering Riverside from Gamma and heading straight ahead until you can see Waterfront Booze. Bear left and you should see Software Refinery's hangar door as you approach the river. The don't buy anything. They sell software for your Moth. Rumor has it they pirated the software from Software Shack and that their main goal is producing some kind of game.