Buying a car in the SW USA (CA, AZ, NV) questions!

Hello all.

I am in Michigan. A buddy and I plan to fly out to the SW USA – Southern CA, Las Vegas, and Arizona – buy a pair of 1970’s-1980’s old cars, and drive them back home cross country. Or, as far as either one makes it! We are not ignorant kids, we’re both in our 40’s. Just doing it more for the fun and adventure, and less about the cars themselves. If we manage to snag a few cool cars that are typically not common in the Great Lakes region, bonus! Maybe even an early 70’s A-Body to go with my 65 Dart!

My Question for the forum folks is this: What special procedures or considerations do we need to account for when buying a 70’s or 80’s car in CA, NV, or AZ? Such as smog/emissions, title transfer process, getting temp tags for the drive home, all of that. ANYTING that could potentially result in us buying a car and not being able to drive it away.

For example, Michigan is about the easiest state to buy an old car in! No emissions tests. Temp tags you can get at any car dealership or Sec of State (DMV) office. And heck, we do not even need a notary public to stamp a transferred title! So knowing about any special considerations for buying a car in CA, AZ, or NV would be very helpful!

Thanks, all!

JMG