H Sandy
I’m not sure if your referring to my thread, or not, but I did build a truck using only Zbrush. I didn’t make a tutorial about it but there are a lot of post showing the progress and some discussions on what I did to get to that point, at the time. I did do a tutorial for using shadowbox to make some parts for the bicycle I built with Zbrush. Most of the stuff I’ve built has been hard surface projects and many of those are vehicles. Here’s the link to my thread. I hope you find something that will help you out in there.
http://www.zbrushcentral.com/showthread.php?103063-Ezra52-Sketches-Nudity-Maybe-Later
I never made a tutorial about making mag wheels either but I think Gary Komar did in his thread. Gary also makes a lot of hard surface projects and he also has a lot of vehicle type projects. Here’s the link to a couple of Gary’s thread.
http://www.zbrushcentral.com/showthread.php?170433-Billet
http://www.zbrushcentral.com/showthread.php?164760-Jet
You may also want to take a look at Pixolator’s two videos below where he shows the ‘making of’ a motorcycle. It’s not a tutorial but if you watch closely you can get a lot of insight about how he works to get the parts made.
See post #73 on this page.
http://www.zbrushcentral.com/showthread.php?95181-Making-Time-For-Art-2-Now-with-tutorial-movie-PART-2/page5&pp=15
and post #148 on this page.
http://www.zbrushcentral.com/showthread.php?95181-Making-Time-For-Art-2-Now-with-tutorial-movie-PART-2/page10&pp=15
Hope you find some information that helps you understand how to better utilize the Zbrush tools and possibly some inspiration too.
Take care and have fun brushing.
Ezra