get the ONR (optimum no rinse), follow instructions, and you will be fine.
there are even videos on youtube how to wash the car this way, looks perfectly fine, and clans and shines the car right up.
the only thing that you cant get to unlike conventional car wash is for example wheel wells with hard spray off.
32oz is like 12 bux, and you can also get a full gallon of this stuff.
heres a quick how-to, although washing a car is not science
http://autopia.org/forum/detailing-product-discussion/89845-onr-how.html
and here is the Optimum forum, great info there, take a look at the how to section, even shows how to wetsand on a new Boxster
http://optimumforums.org/lofiversion/index.php/
and this is the tutorial, much better than one above, from that site
http://optimumforums.org/lofiversion/index.php/t424.html
here is a video washing the silver porsche, once there you can click on the right for other videos
http://video.google.com/videoplay?docid=-4910183452379827390&hl=en
and here is a black one, much better to see
http://video.google.com/videoplay?docid=-2077855946412498290&hl=en
BTW, quick Q, instead of drying with a towel, i like to use the leaf blower, would this be a bad idea after ONR?