Hi Bigjobs,
I used to live on the west side of michigan, so hopefully i can help a bit.
Getting there, easiest way from BNE is QF to LAX then NW direct to DTW. NW and CO share a nice new terminal there in Detroit - all the others (incl AA) fly into the old dingy terminal. But, all depends on your FF allegiances - would be a good candidate for an AA plat challenge, going via ORD or DFW.
Anyway, once in Detroit public transport is pretty minimal. Detroit is car country. Traffic is bad at peak hour, but not as bad as chicago, LA etc. I never caught a taxi there (had my own car) but I'm sure they are around.
Not sure where you need to be in the city, but if you get some spare time there are some nice places down by the river - Belle Isle is a cool park on an island in the middle of the Detroit River. If you have more time, venture north of Detroit up I-75 and visit the northern part of Michigan.
In May the weather should be warming up (relatively speaking) - maybe highs of 10-15 degrees C. Although it did snow there in early May a few years ago, so take some warm clothes.
http://www.weather.com has lots of weather info.
If you Google "Visit Detroit" there are lots of websites they've set up, which will give you some more information.
Detroit isnt a beautiful city, but there's some interesting stuff there. Go and see a Detroit Tigers baseball game at Comerica Park - they'll probably lose, but its a good experience anyway
Eat some hot dogs, drink some Bud, and you'll be feeling like an American in no time
Enjoy your trip
James
