The only meaningful price comparison is to start with the MSRP shown on the window sticker. Did you pay more or less than that. When I bought my RAV4 several years ago, I paid MSRP minus $750 Costco discount. When I bought my 4Runner many, many, years ago, I paid MSRP minus $2000 Costco discount. When I bought my son a Prius two years ago, we paid MSRP, nothing more or less. Some dealers will charge more than MSRP calling it "market adjustment"; they would never have my business.

Invoice prices are meaningless. They are a tool the dealers use to try and convince you that they gave you a good deal. The dealers actual pay less than invoice when they acquire a new car from the factory/distributor.

Tax, license, an other fees are determined by where you live, so cannot be included in price comparisons across the US/Canada.

 

What has worked on many models is MSRP - 10% for an approx OTD+++

Back of the envelope example, MSRP 42,000 - 4,200 - 37,800 (Now add fees, tag, tax)

However, if I know and have research that a particular factory program like month-end volume, fleet sales bonus etc, is available, I negotiate using that data
Also applies to quarterly returns to dealer by factory and floor payments.

No car dealer owns the cars, they are on credit and there are costs keeping inventory, I use this data to move cars that have remained unsold