the whole antenna setup is aftermarket. went to a toyota dealership to check it out and found out the whole thing was changed, so i would need to buy the stock mount, nut, and pole just to get the s2000 antenna to fit. it'll probably cost me around $100 to get everything. i'll probably just end up keeping the old antenna, but it sucks that i spent $20 bucks on the s2000 antenna and i cant use it.