Start a website where you fill in your information, pick the desired car and specs, and enter the payment terms you are after. If a dealership has what you want and can offer it to you at your desired terms, they can contact you and make a deal.
I am so damn tired of calling and emailing dealerships just to be lied to again and again and again...
It would be a real lead generator for dealerships, and cost to match the dealership to the client can be either per car or a monthly subscription. Basically, a car broker app. Dealerships can rate your offer and if it is unrealistic, after a few downvotes, the buyer gets notified and can either delete or adjust.