More than most trades, auto repair fights a default assumption of being taken advantage of. Almost everything that works is a response to that.
What helps: written estimates before work begins, photographs or video of the actual fault sent to the customer, showing the replaced part, plain explanations of what is urgent versus what can wait, and a warranty stated in specifics rather than in the word ‘guaranteed’. Certifications and technician qualifications displayed, because they are one of the few external signals a driver can read.
A page explaining how you diagnose and quote — and what happens if the job turns out to be different once it is open — is unusual, useful, and converts the sceptical.