Tips on Buying Cars: Car Negotiating, vocabulary words, finance deals

Question
Greetings,
I've heard that it's best to start the haggling $2000 below the invoice. Since the invoice is usually around $1500 below the MSRP, the starting offer for a car with an MSRP of $18685 should be $15185 (or $3500 below invoice). Is this a ludicrous offer or can the starting offer even be lower than that? And do I have to mention vocabulary words such as "holdback" and other factors that contribute to the "dealer cost" to the dealer in order to get a lower price? If so, what is the best way to use these terms in a sentence to gain the upper hand? If not, should I just tell him what my starting offer is going to be ($3500 below MSRP/sticker price) and he'll assume I know some stuff about "dealer cost"? Lastly, would bringing a Edmunds.com TMV price report of the car give me an advantage when trying to get a lower price? Thank you for your help.
P.S. The same person who recommended starting an offer $2000 below invoice said he bought a new car at $17550 when the sticker price was $26650: No trade, no special finance deals. That's sounds quite unbelievable.

Answer
Derrick,

Thanks for your question.  I would tend to disagree with the advice that you have gotten on where to start the negotiating process.  Invoice on a new car is pretty close to the actual cost of the vehicle cost of the vehicle.  Now, with that being said, dealers get what is called Holdback on a vehicle that lessens their cost on the vehicle.  Holdback on a vehicle in this price range would be somewhere between $300 and $400.  I would always bring anything with me like the edmunds.com TMW price report. That just helps your cause.  The person that gave you this advice, probably got a rebate on the vehicle to get it that low.  Your negotiating needs to take that to take that in mind when getting to a price.

Hope this helps.

Thanks - JB