Alright, why is it you're willing to, essentially, take money from someone else's pocket?
I can't say for sure, but I assume there are some dealerships that work on commission. If that is true your kindness of giving bottom line pricing may reduce the pay the salesman/dealership takes in. Maybe that dealership needs to make 10% profit to keep the doors open and now has to raise shop rates to close the gap. I mean the point of having a dealership as a business is to make a profit.
Not saying I don't like your approach. Just saying you might be making enemies at the same time while gaining no business of your own.
Don't "think outside the box".
There is no box.
Do it correct, or do it twice.