When we fly out of DTW, we use either the Springhill Suites or the Fairfield Inn. Both are Marriott branded, they are right next to each other, they both offer free breakfasts and the parking is only $10 and it covers 8 days. When you check out, you simply drive to the parking lot, tell the attendant what airline you are flying and they will have a shuttle escort you to your parking space. The driver will assist with you luggage, transport you right to the terminal and give you a ticket with your parking space on it. When you return, there will be a shuttle waiting for you (or one coming shortly) and they take you right back to your car. They send a new shuttle as soon as one leaves so there is very little waiting.
Our most recent experience was in June 2012. We were a group of 15 people with 3 vehicles and 4 rooms. It was so simple! My dad was very hesitant to fly out of Detroit (since the GRR airport is only 15 minutes away) but since he was paying for all 15 people, he saved almost $1500 even with paying for all of the rooms. That kind of savings was hard to ignore so he decided to try it and afterwards, he said it was so easy, he would do it again in a heartbeat

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