Oscar,
Food for thought, your conversion rate is far more elusive than you think.
For example, think of the impact to your conversion rate if you are a Chevy store. Watch the conversion rate shrink! The Chevy shopper demo totally changes, the number of Chevy stores per capita gets far higher, the distance between Chevy stores shrinks. Factor in Brand loyalty too. Woops! Don't forget to factor in Brand Bartering. Chevy buyers expect to barter so leaving your name on a form is not always in the shoppers best interest.
What if your inventory shrunk to 25% of its current size. What of your conversion rate now? Far smaller for sure! Another twist would be, what if a new competitor rolled in with 2,500 new Acuras on the ground?.. ouch.
Also, we're well into the 4th, 5th, 6th time that a buyer has used the internet to buy a car. Does your internet process reward the web shopper with good info (so they'll use it again for the next buy?) Another factor, how good-or-bad have your competitors been at rewarding email use? Do they have inferior email practices that, over the years, have trained the loyal Acura shopper to only use
you to email to?
See where I'm going? Conversion rate is created by... everything (not just the site).
Conversion rate connects to Distance between stores, Inventory depth, brand demographics, dealer reputation, dealer email commitment history, dealers per capita, oh.. did I mention the web site