At one point they had an MP3 capable version of the typical AM/FM/CD unit that was used from 2003-2008. It was an option in the later years, maybe 2007-2008... It had 'MP3' on the face in big white letters.
Not sure what the product mix was like when new, it may be a needle in a haystack to find one of those if it was an infrequently ordered option
Edit: Here is what that one looked like...
There was also someone here who installed a
Scion Pioneer unit.
Though honestly at this point, it may be worth it to pick up an aftermarket yet stock-looking double-DIN.