If you put the ultimate company name (the service the customer is trying to contact) and then your phone number then that's passing off, tortuous malfeasance in European TM law (and I'd be highly surprised if it's allowed in the US).
If you want to advertise a business lookup service the ethical and legal way is to put your own name, then something like "contact Mountain View Cars through SuperHappyConmen.com on 123-456-7890, we are not associates of Mountain View Cars".
If people want to buy tracked phone numbers for their ads they will, I'm more than happy for you to provide them. But it's not your choice whether they take on your service or not.
If you want to advertise a business lookup service the ethical and legal way is to put your own name, then something like "contact Mountain View Cars through SuperHappyConmen.com on 123-456-7890, we are not associates of Mountain View Cars".
If people want to buy tracked phone numbers for their ads they will, I'm more than happy for you to provide them. But it's not your choice whether they take on your service or not.