Big mistake to use the Ryan. Switch to Lake Shore Drive via 55 at the interchange near the Loop, then follow the signs through Hyde Park, onto Stony Island, and onto the Skyway. Best 2 bucks you'll ever spend. Bonus: if its past noon, stop by Barbara Ann's or Lem's for a tray of tips and links. Call ahead for any order of tamales and/or BBQ to be sure of hours and availability.
Though, to be fair, there is some quite good BBQ in the same style in Benton Harbor, minutes away from St. Joe's. Willie Lark & Son's BBQ and Car Wash is the real deal. Not as exotic as BBQ and hourly motel, but still. Note the three huge outside smokers.
http://www.goswm.com/go_htm/southwest_m ... index.htm#
For good "non-Chicago/Mississippi" 'cue (esp. pulled pork and brisket, plus great beans), Piggin-n-Grinnin is a few blocks away.
http://www.piggin-n-grinnin.com/
And in case you aren't aware of the places in St. Joe's with good fish, I like Clementines, by the river, for perch.
http://www.ohmydarling.com/
But you asked about tamales in Chicago--
The natural thing to do is to jump off of the Ryan at 18th Street (Pilsen), pick up the tamales at Milagro or other recommended spot, drive south on Ashland, jump on I-55, take that to LSD and stop by BA's while on Stony (Right on 75th to Cottage Grove, south a few doors, then back to Stony to get on the Skyway). Of course, there's some great Mexican in rural Michigan 15 mins or so from St. Joseph at the markets that serve the orchard and vineyard workers (a la the taco trucks of Santa Rosa), but that's a different post.
If you get hungry on the way to Michigan, check out ReneG's recent posts re NW Indiana (there's a Schoops in Michigan City).
Best of luck.