Hallo to Ecomodder.
May I ask you of your age, skill level and timeframe you are expected to deliver results to your team? That is important for precise answers.
Now to answers:
1) here is the link I got after minute google search:
Science Buddies: How to Build and Use a Subsonic Wind Tunnel
(but I am sure you somehow missed it during your research, and you really tried various combinations of "wind, tunnel, aerodynamics, wind tunnel" terms in google search, and this "do it for me please" forum post was your last resort).
2) More intelligent and experienced people here would tell you your effort is futile, as 1:10 scale model aerodynamics is completely different than aerodynamics of real car. To test 1:10 model you need cca 10xmore wind speed than in reality. Look at
https://en.wikipedia.org/wiki/Similitude_(model). (That´s why is hour in wind tunnel so expensive and why automotive industries is still building new tunnels. You can either read Phil's aerodynamics seminars (first post in this forum, but I am sure you are now reading it) and choose one from pre-researched aerodynamic shapes, or choose one from already existing aerodynamic cars or velomobiles in existence (there are dedicated threads to interesting aerodynamic cars and velomobiles)
3) if you really mean it and want to test scale models, (and have plenty of time and money), consider using water tunnel. there should be someone who started a thread about it. use search button
4) some basic shape evaluation you can get from software tools - flow illustrator (
Flow Illustrator - free online flow simulation tool ) looks like a toy, but at least helps you to visualize the flow. There was even discussion here on ecomodder, where you can educate yourself too. use search.
But without basic understandig of aerodynamic principles are all efforts likely to fail (Halliday, Resnick, Walker - physics lessons for start, then perhaps any college physics book, than aerodynamics)