Be sure to ask for a written estimate before any repair work is done on your car. Mechanics generally can't know exactly how much a job will cost until they discover the extent of work needed. A garage should give you the option of approving any repairs over a certain dollar amount. A lot of times you may have to ask the mechanic for a general figure based on the maximum amount the repairs on your car might cost. You should be able to set a maximum amount on costs that can't be passed without your verbal or written approval. The written estimate should include a calculation of potential labor charges and parts that may be needed. To make sure that all charges are accounted for, compare your estimate with the final repair bill. You might even ask for your old parts back to make sure that everything listed as having been replaced is accounted for. Contact a qualified auto mechanic for more information on auto repair estimates.