815 ILCS 306/20
When an estimate is required to be presented to a consumer, a motor vehicle repair facility shall disclose to the prospective consumer an estimated price quotation or the option to waive the price quotation by completing the following statement with the consumer's signature:
"You are entitled to a price estimate for the repairs you have authorized. The repair price may be less than the estimate but shall not exceed (1) any price limited estimate or (2) any parts and labor estimate by more than 10%. Additional repairs may not be performed without your consent. You may waive your right to a written estimate and require that you be notified if the price exceeds an amount you have specified.
You may waive your right to an estimate, which gives the motor vehicle repair facility the right to set the price without your permission. Your signature will indicate your selection.
(a) I request an estimate in writing before you begin repairs. Signature .................................
(b) Please proceed with repairs but call me for approval before continuing if the price exceeds $ .......... Signature ................................. (c) I do not want an estimate and you may set the price of repairs.
Signature .................................
Date ..........
Time ..........
This estimated price for authorized repairs will be honored if the motor vehicle is delivered to the facility within the time period agreed to by the consumer and the motor vehicle repair facility."
However, transactions involving the retail purchase of merchandise when a facility installs the merchandise as part of the transaction at the discretion of the customer for a firm price are not included. These transactions shall include but not be limited to tires, batteries, oil, and lube jobs.
815 ILCS 306/20