Stock WRX is 205/55R16 (24.87" OD) or 215/45R17 (24.61" OD). Quoted OD sizes do not include squish and came straight from a random tire stores online calculator.

IMHO, all designs should be based on that O.D. unless FFR is planning on providing wheels and tires with the kit OR they are planning on blatently scrapping the $15,000 on the road target. Now, if those OEM sizes leave the wheelwells slightly unfilled, that's expected and OK - But they should at least be acceptable to look at.