What you're describing is (or used to be) called fax-blast car buying [1], and the best move once you've firmed your decision on exactly what you want is to contact the fleet sales managers with either a quote request, or an offer to buy - repeating the offer process until you stabilize on a overall discounted price.

In my case, I worked with 3 dealerships (one where I test drove the vehicle and 2 other fleet managers. I ended up going with the original dealer because I had more rapport, he was flexible on pricing and agreed to complete the paperwork and hand over the keys at our house (we had newborns) - I had no idea this was even possible, and was a nice completion to the purchase experience.

[1] http://www.edmunds.com/car-buying/blast-fax-car-buying.html