Wis. Stat. § 346.72: Garages to keep record of repairs of accident damage.

The person in charge of any garage or repair shop to which is brought any motor vehicle which shows evidence of having been involved in an accident shall keep a record of the date such vehicle is brought in and the nature of the repair, the name and address of the owner, and the make, year and registration number of the vehicle. Such record shall be kept in the place of business during business hours and shall be open to inspection by any traffic officer. Shop records normally kept by garages and repair shops are adequate for the purpose of this section if they contain the information specified in this section.