cyanide,
I did some research on this type of marketing for the last start-up I worked for. We were looking into bus wrapping. (Where the entire bus is wrapped in a vinyl banner) It is very expensive.
I would definitely look into the cost and travel time. Where are the vehicles parked when not on the road? Are they in a parking garage, or are they parked in the front corner of a corner lot? And what kind of traffic runs that area? When they are on the road are they running through your target market area? (i.e. hosting providers might see a greater return if the vehicle ran through suburbs rather than a manufacturing industry.) And what is the average travel time for each vehicle? Are people driving these vehicles 5 miles a day or are these vehicles covering 100’s of miles each day? Are they posting cheesy magnetic door panel banners, or are they going to do a vinyl wrap over the vehicle? Who has control over the design? And what kind of company is it? Who is going to drive the vehicles? Do you want your company to be a liable participant in an auto accident? Even if it is not your vehicle, your name is all over it. These are all questions we asked when looking into this type of campaign.
I would check out a couple companies that deal in this market such as:
http://www.ad-wraps.com/
http://www.adsonwheels.com/Car_Wrap_Main.asp
http://www.onpoint-marketing.com/car...dvertising.htm
(I am not promoting any of these companies) Get a hold of some of their clients and find out what their results were with this kind of marketing program.
Hope this helps. Best of luck to you.