The estimate is edited on the order
Every service order carries its own estimate: labour and parts, with quantities and prices. It changes as the work proceeds, because you rarely know everything that needs doing at the start.
What is on the estimate is what reaches the invoice. It is not retyped.
Off by default, on when you need it
The module is off by default and enabled from settings. It is not restricted to one industry: any company that works to order can use it, not only vehicle workshops.
Worth knowing
In a workshop the conversation with the customer is about the estimate, not the invoice. If the estimate lives in a notebook and the invoice in another system, you both discover the difference at the till — which is the worst possible moment.