AVS, aka AutoventShades mfgrs and sells them. You can find them for sale at PepBoys, Autozone, and even WalMart. They are in a distinctive looking yellow package and if you find one labeled Explorer (and for your same year) then they will work on your ST.
Personally I like the ones that do go into the window track. To me they look a little cheap if they don't. I am debating getting some of these as well....probably will when I get my front windows tinted.
Not sure if they make the outside mount ones for the S/T. I feel the in track one have a lot of wind noise because there is no felt between the window and visor.
What year ST do you need them for? I bought a set on Ebay for my 07 thinking they were the in-channel style but they are the outside mounted type. You can have them for $40. They have never been installed. Summit sells the same thing for $52.99. Auto Ventshade p/n 94819.
I have been trying to decide whether to get in channel or outside mounted for my '07. I don't see how the in-channel could fit let alone not have air noise? I've seen both types on Ebay though.
Last truck was a Ranger. I installed the "in track" visors........thereafter had increased wind noise and power window problems.
I agree, "in track" has a much better appearance (finished look), but the "out of the track" type will eliminate any power window problems and shouldnt increase wind noise.