From the announcement:
We’ve taken stock of how to supply you with plenty of Bolt Action vehicles at a great price. The result is our new ‘Wheels of Steel’ special offer!
Wheels of Steel works for everyone – simply buy 3 or more Bolt Action vehicles (any vehicles!) and you will receive a 10% discount off of all three! The discount is automatically taken care of in your shopping cart so all you have to do is pick three or more vehicles.
With lots of people starting out in Bolt Action for the first time, we thought this is a good way to help people get started. It also works out pretty well for all of you building Armoured Platoons too.