Even if you’re mainly going to be in downtown Detroit, it’s definitely worth it to hit Royal Oak (just take I-75N to I-696E and get off on the Woodward exit, turn right onto Main). Lots of great food, good shops, and nice bars. Also, Birmingham is the more “upscale” shopping area (as well as Somerset Mall). You can use google maps to locate them, and they are definitely worth the 20 to 30 minutes it takes to get there (in case you didn’t already know, there’s really not much that is actually in Detroit besides the monorail, Comerica Park, the Fox Theatre, and the Bridge to Canada.