What would happen if your business only accepted new customers referred by your current customers? No more advertising. No more discounting. Referrals only. Would your business grow, just survive, or quickly die? If the thought of depending on referrals alone frightens you your problem is not auto repair shop marketing – it's service quality.
Are you as good as you think you are?
If you are not getting frequent referrals from your customers your service quality needs improvement. Depending on advertising and discounting for new customers is a very vulnerable and costly position to be in.
Charge a premium
Wouldn't you prefer to be able to charge a premium rather than having to discount to attract and keep new customers? If all your customers came from referrals could you not charge a premium and stop discounting? New customers referred by long term, quality customers will not be one time bargain shoppers – they will be loyal customers interested in high value, quality service - high value customers who will bring in more quality customers.
Focus on the good customers you have and less on on automotive repair shop advertising. Ask for referrals. If your not getting them ask your customers what would make you more referable. Build your customer driven marketing.
Are your referrals telling you how good are you?