DON"T LISTEN TO UNINFORMED PEOPLE. i hate when people just regurgitate what they hear on the internet and perpetuate the damn lies! lol
just like you can fit 15" wheels on a 2004 tacoma that comes with factory 16" wheels, you can fit 17" wheels on the tundra... just need to do a little grinding of the caliper. but this is really is dependent on the shape of the wheel you buy and how much room you have to work with. walker evans racing is working on their beadlock wheel for our truck. they don't make 18" wheels, only 17" or 15". last time i spoke to them, they had drawings of our brakes laid out but i haven't heard if they are done designing the wheel yet.
there is a large list of 15" wheels that fit the tacoma on tacomaterritory.com. once people start buying 17" wheels and fitting them to our trucks, we can start a similar thread to INFORM PEOPLE. good luck!