Would you pay for this service?

[Conan71]

I'm not afraid to negotiate, nor is it difficult to figure what "invoice" is on a vehicle so I'm not a good potential customer for you, but I'm happy to offer some suggestions.

I've got a background in the industry.  I think your consulting fee is high, perhaps you should think about a different business model of working with a certain number of dealerships and make 1/2 your fee on the front from the customer and 1/2 on the back from the dealer.  You are bringing them a customer, after all.  Perhaps you could structure it as a percent of the amount you save the customer off list to the sales price.

One mistake buyers do make is pissing off the dealer by making a ridiculous offer below invoice and trying to make the dealer think they can refer x amount of relatives and friends.  Congratulations, you are the 20th person who tried that today.  Car dealerships are a lot like casinos, the house always wins.  It's not so much making a low ball over as it is being a completely obnoxious prick when doing it.

The actual negotiation for the purchase price isn't all that difficult.  It's when you get into the disposition of your old car it gets hinky, especially if you are looking to trade it. 

My own specialty was F&I or the "business office".  It never failed, someone would come into my office gloating about beating the house down to nothing on their deal.  It was up to me to make it back.  "Sorry Mr. Dingle, you have a few dings on your credit, your rate is going to be three points higher."  Doc fees, buy down points, extended warranties, credit life & health, gap insurance, etc.  An hour later, the house had just made a gross profit of $4000 on a "nothing" deal.

[waterboy]

You might consider using the model "buyers agents" use in the real estate industry. A real estate agent really only represents the seller. Buyers agents do not. I fear that if you are doing both sides you're more or less a bookie balancing the books and may lose credibility.

[Townsend]

With the ease of access to all pertinent information on the internet, the service is available at your fingertips.

Everything can be done over email, no face to face at all.  Hell, the vehicle can be delivered right to your door and you never have to say a word to a sales person.

I've done it locally and over state lines.

[waterboy]

Which would be fine if everyone who buys a car is also computer and internet savvy, online purchasing was beyond reproach in credibility and you do your test driving locally. That is a smaller subset of the population than you might think.

I think there is a niche there, just not sure how big and worthwhile it is.

[SDTULSA]

I know with Honda as a example dealers in Oklahoma cannot sell a car to a "Broker" or they lose cashback and/or holdback on the car.  I work as a salesmanager at Joe Marina Honda and we have Brokers call us often but we have to decline to stay with Honda rules.