My 2 favorite things to see people bitch about are labor cost and maintenance.
Labor cost - they bitch because it’s $150 an hour - billed by “flat rate” times (flat rate is what the manufacturers/guidemaker allows for a service). If someone says it takes 1 hour - you make 1 hour labor - regardless of you spend 20 minutes or 3 hours doing it. Of course you get “it only takes 20 minutes” out of people - and that’s correct. But you gotta set up - so the job and then do a QC before delivery - that time counts too genius.
Then there’s the cost of tools and subscriptions you don’t factor. If anyone has ever bought stuff off the snap on guy - you know tools ain’t cheap. Worse - the subscription to data shops have to pay for - I’m not exaggerating when I say it can easily be $1500-2500 a month for a subscription for data. Fix 250 cars a month - that’s a busy month and it helps - but a small less busy shop that does 50 pays the same rate - suddenly you need to cover $30-50 a car just to have the info to work on them.
Oh and the certification/training - again $10k per year for a manufacturer isn’t uncommon. That gets you 2-3 techs training for a year. Again - works well until the tech goes and then quits 2 weeks later - then you gotta pay to send new guy to same training.
Maintenance- YouTube changing cabin and air filters and do it every 6 months - super easy - cheap and you will never be tricked into paying for what you don’t need. Brakes - use a good independent mechanic - oil change too. I don’t trust the drop outs assigned to express lane service - ever. Keep up on maintenance and the big problems are significantly reduced overall - better yet - buy 6 and 8 cylinders without turbos or extra “hybrid” crap and again - way less problems.