4 or 5 years ago, we were looking for a late model used pickup. We made up a list of what we wanted and I started looking online. At first, the only one we could find with everything we wanted was located in Hermiston, OR, about 400 miles from here. We later found one much closer.
All of the larger dealers now use the web to list their inventories. It's a very handy way to shop.
Start out with a simple search, like 'Montana tundra 2015'