Mandate the Auto Industry disclose their true cost as opposed to theoretical invoice cost if used in selling a vehicle

We all have been subject to the Auto Industry's suspect tactics when buying a car. They wave "Invoice Pricing" in front of you like its the cost THEY pay for the car. Are we supposed to believe while they sell a car for $44K they "buy it" it for $43.5K!?? This is misleading and should be stopped. If the Auto Industry Intends on using "cost" as a sales tactic they should be obligated to share true cost and not use an Invoice Price which is based on no true exchange of money.
The fact is that typical retail markup is 40%-they expect us to believe that invoice is what they pay. It's dishonest and untrue. They should be held accountable in the instances where they misrepresent the truth in selling their product and should be required to prove their cost only IF they use it as sales tool.