Best Photoshop settings for high-resolution vehicle wrap design?

Ask the people who are creating the wrap.  They are the people who best know their requirements.

Note:  This presupposes that you didn’t start this thread just to spam us with the link to your website.

What is the design? 

If it consists mainly of sharp-edged graphics/logos/… then it might be better to create it in a vector oriented application right away (edit: Illustrator for example). 

Otherwise the usual applies (even if it may sound glib): Please ask your print provider. 

For large-scale printing 600ppi at a scale of 1:10 usually suffices (so an effective resolution of 60ppi), but best talk to the actual producer. 

They might need CMYK-pdfs but depending on the design working in a profiled RGB may be fine.