Definitions Used in the Car Sales:
MSRP: Manufacturer's Suggested Retail Price. This is listed on the window sticker and is often call the List Price. However dealers can sell a vehicle for what ever they want.
Dealer Invoice: This the price that a manufacturer charges its dealers. Many people mistake it for actual cost.
Hold Back: A hidden amount that manufacturer give back to a dealer. It is a percentage of the MSRP or the invoice price.
Dealer hold back is a hidden profit manufacturers apply to the invoice prices and give to the dealers. Dealers are allowed to use this profit anyway they see fit. You can use it to leverage for a discount.
Rebate: A discount or incentive that is supposed to be given to the consumer.
Dealer Cost: The actual cost a dealer pays for a vehicle. Invoice - Holdback - Rebate = Cost.

By knowing how much profit dealers are making, you are in a position to determine how good a deal you are receiving. If you can land a price quote within $1000 of dealer cost, you are getting a great deal. In many cases you will see a price well below dealer invoice because of large rebates and hidden incentives called dealer holdback.
Refer to internet pricing services that are easily available online