Frankly, we understand why Fisker Automotive and Coda Automotive might not want to release their sales data.

Both companies have struggled mightily with delayed rollouts of their first plug-in electric cars.

But Tesla Motors just nailed its promised late-June first delivery date for the Model S electric luxury sedan, so we expected more.

You would think the company would now try to behave like the adult car company it wants to be seen as.

In one respect at least, you would be wrong.

The background: On the first business day after the end of a calendar month, the auto industry engages in the monthly ritual of sales reporting, in which all carmakers release the number of cars--broken out by model--they delivered to buyers during the previous month.

All automakers, that is, except for small startup electric-car makers. Both Tesla and Fisker refused to provide monthly sales figures; as private companies, they didn't have to.

Quarterly numbers, delayed

Once Tesla Motors [NSDQ:TSLA] became a publicly traded company, it had to provide minimal sales data to stockholders. And it does, buried deep in quarterly disclosure documents filed with the U.S. Securities & Exchange Commission filed weeks after the quarter ends.

(Fisker and Coda still refuse to give any sales data beyond off-hand, unverifiable comments from executives.)

Tesla Motors, Palo Alto, California

Tesla Motors, Palo Alto, California

Now Tesla has moved past its low-volume Roadster. The company says it will build a regular stream of Model S luxury sport sedans to deliver to the 10,000-plus buyers it says have given it deposits.

We asked Tesla communications manager Shanna Hendriks when Tesla would provide sales data--June's figures are due Tuesday--but she said the company had no intention of providing monthly figures.

"We will continue to report figures for Model S reservations and deliveries on a quarterly basis," she wrote, "as has been done in the past. "

In other words: We don't have to play by the same rules as other car companies.

"A mark of legitimacy"

We think that's a dangerous attitude; more importantly, so do two industry analysts we spoke to.

"If you intend to call yourself an American automaker," said Aaron Bragman of IHS Automotive, "you need to publish your figures, just like every other automaker."

"Want to be considered something other than a sketchy operation with little transparency and an uncertain future?" he asked, pointedly.

"Then start opening the doors to inspection, and start providing information by which you can be measured objectively. It's a mark of legitimacy."

Cash flow obscured

Dave Sullivan of AutoPacific echoed the sentiment.

"Niche companies like Lamborghini, Bentley and others release sales data on a monthly cadence," Sullivan pointed out, "so there's no excuse other than not having to play public relations defense on a monthly basis."

"It'll be up to investors and stockholders to demand monthly transparency" from Tesla, he said, but "it'll be difficult [for Tesla] to show progress without releasing sales data" and, he added, "it'll be hard to judge cash flow."

Tesla Motors, Palo Alto, California

Tesla Motors, Palo Alto, California

Sullivan suggests the information blockade may hurt the company: "Tesla's barricade won't help opinions on Wall Street."

He noted that Azure Dynamics--the conversion company that built the Ford Transit Connect Electric, now bankrupt--was also reluctant to discuss sales data.

To which we can add that Think North America stopped providing monthly sales a few months before its Norwegian parent company filed for bankruptcy.

"If you're truly proud of your product," Sullivan concluded, "you won't shy away from sales data or reviews from the media."

What does Tesla want to hide?

So, we close with questions: Does Tesla's reticence reduce financial transparency?

Do investors, analysts, and its many, many fans have any right to know exactly how many Model S cars Tesla delivers each month--just as they do for all other car companies?

And why would Tesla be scared to say how many cars it sells?

Leave us your thoughts in the Comments below.


Follow GreenCarReports on Facebook and Twitter.