The legislature finds that the practices covered by this chapter are matters vitally affecting the public interest for the purpose of applying the Consumer Protection Act, chapter
19.86 RCW. Violations of this chapter are not reasonable in relation to the development and preservation of business. A violation of this chapter is an unfair or deceptive act in trade or commerce and an unfair method of competition for the purpose of applying the Consumer Protection Act, chapter
19.86 RCW. In an action under chapter
19.86 RCW due to an automotive repair facility's charging a customer an amount in excess of one hundred ten percent of the amount authorized by the customer, a violation shall not be found if the automotive repair facility proves by a preponderance of the evidence that its conduct was reasonable, necessary, and justified under the circumstances.