NEW YORK (TheStreet) -- Tesla Motors (TSLA) - Get Report stock closed higher by 4.13% to $210.12 on heavy trading volume on Wednesday after a group of investors demanded changes to the company's board to make it more independent.

CtW Investment Group is urging the electric automaker to add two independent directors to the board and to split the roles of CEO and chairman after CEO Elon Musk offered to acquire SolarCity (SCTY), where Musk is a shareholder and chairman, Reuters reports.

The group, which has about 200,000 Tesla shares, is also demanding the $2.8 billion SolarCity proposal to be reviewed by a special committee that would include two independent directors.

"The fiercely negative reaction to the proposed transaction only highlights the flawed (corporate governance) process and underscores our continuing concern about governance at the company," CtW Executive Director Dieter Waizenegger said in a letter sent to Tesla, Reuters added.

By the end of the trading day, 5.84 million shares of Tesla had been traded, compared with its average daily volume of 5.62 million shares.

Separately, Tesla Motors has a "sell" rating and a letter grade of D+ at TheStreet because of the company's deteriorating net income, generally high debt management risk, disappointing return on equity, weak operating cash flow and generally disappointing stock performance.

You can view the full analysis from the report here: TSLA

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this article's author.

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