Williams is NOT doing a BTO system, BUT they are limited production to set numbers on Chuggington.
Here are the numbers;
Brewster only 480 made
Wilson only 480 made
Box car only 480 made
Hopper(B)only 300 made
Hopper(Y)only 300 made
Pass. car only 480 made
With over 24,000 TCA members alone and less than 500 pcs. made they will sell out!