Author of the Ice and Edge Series
I checked the SuperShuttle website for info on pricing in Detroit . I've used SuperShuttle about 6 or 7 times in different cities and Detroit is by far the most expensive...I was shocked.
To go from the Detroit Metro Airport to a downtown hotel is $125 round trip in a car and $250 round trip in an SUV for 1 person. There may be lower pricing if you are traveling with someone and wish to share the car or SUV. It does not appear that they have a shared van (which I've used everywhere else) available.
The quote for Lyft from the airport to downtown is only $25-$35.