I use Preiser 65602 Unpainted 1/45 24 Seated People. The 65602 set comes with 24 figures, including 3 Adults with babies. I have painted 78 sets of 24 so far. That's 1,872 Seated figures that I used in my Atlas O and Lionel 21" passenger cars. I save $120.00 per 24 pack by painting my own figures. The same twenty-four figures come in five separate Preiser painted packages that cost $155.00 plus shipping. These five sets have been out of stock for over a year. I figure I have saved $120 times 78, or $9,360.00 by painting the figures myself.
I paint the figures in this order: 1. Flesh, 2. tie, 3. shirt on either side of tie (edging the tie for a sharp clean line) , 4. Suit, 5. Hair and 6. Shoes. I paint a box of 24 at a time, using one color for all men's suits (flat brown, blue, gray, light brown, then repeat on the 5th box.) The women's clothes are pastels: (flat blue, pink/cherry, yellow, green, and lavender) I repeat the color sequence every 6th box. With the women's clothes, I paint the tops the color and leave the skirts "white" or "tan". The two colors of clothing on the women adds to the color contrast inside the car. I paint the passenger car seats a cocoa/chamois tan. Table cloths and toilets are flat white. Desks are Testors Flat "Earth Red" brown. (For my seats, I mix Testors Flat "Earth Red" into a bottle of Flat White.
I have to grind the rear ends of the figures with a Dremel "Micro" Chargeable Tool with a sanding drum. This allows me to tilt the figures backward in large seats, or lower them for Dome seats. The newly sanded rear ends accept the Krazy Glue better and makes a better glue joint to the painted seats. I have to vent/air-out the glue for six hours to keep the Krazy Glue from fogging the windows of the passenger car.
I have also used Preiser 68209 1/50 six seated passengers on previous cars, but they are now sold out and out-of-production.