My husband is a mechanic and I read this to him. He said when you ask for estimates, ask "What does the time pay for (tell them the repair needed as told you by the dealership)." They should should ask your make model and year of your car. Then ask "What is your hourly rate?"
Time pay x hourly rate = labor cost. That will give you a ball park of what you will be paying. Some will charge more and some less. But knowing how the repair shops create estimates, it will help you to be knowledgeable and confident when requesting quotes.
The "time pay" refers to the Motor Manual that most repair places refer to when creating an estimate.
Now, this is from me, as far as your rear window, break it accidentally and call a windshield replacement service. They usually will replace it and bill your insurance and the most you will have to pay is the deductible for your car insurance. Sometimes, they will pay your deductible up to a certain amount and if you call the right place, you can get 12 free dinners somewhere.
We have had windows replaced and our insurance has not gone up. The insurance companies expect these things to happen.
About a week after we bought my SUV, I found out the hard way that you can get a 9 foot 11 and a half inch 2x4 in there with the back door shut. However, the 10 foot 2x4 that we bought didn't fit and when we shut the back door it broke the windshield.