Legal ways to collect your bill for auto repairs?

It don't seem right that there's no process to collect, even in CA. I checked, and I have not found anything un-constitutional on Mechanic's Liens in ANY state. Can someone source or prove it? What has changed are the timings and procedures. It seems just filing and recordings are hurdles in themselves. Here's a "recent" link to CA law: CA Codes (civ:8410-8424)
It seems only registered businesses, contractors, have use of this legal procedure. Billy Bob's Part-time Repair probably has to go through small claims.