Car undercoating for rust prevention?

Hey folks,

Got a new vehicle a few months ago and been thinking about getting the undercoating done to protect it against rust for Midwest winters. Hoping I should be okay not having it this winter and getting occasional car washes done for the undercarriage should be suffice.

Can anyone recommend places that do the undercoat spray and share what it cost them? I read woolwax is recommended? Does something like this need to be done professionally or can you get the same product in a can and spray underneath at half the cost?

Are there specific car wash locations that do a good undercarriage wash? I usually just pay $8-9 at your usual holiday/SA location every now and then. Also how often should I get the car washed in the winter...once a month?