You're right on the target. Just keep in mind ZR only sticks as good as what it is stuck to. Zero Rust sets up real quick, but it takes a while for it to totally "cure" but in Texas I'd guess you be ok in about 10 minutes.
Just make sure you give it two coats, at least. One of one colour and the second of a contrasting colour so you can make sure you get it everywhere.
Buddy, do yourself a favour. If in fact you're going to "drive it while you paint it", at least drive slow while your spraying.
