Business Green: US-based car-sharing firm Zipcar has become the latest green company to file for an IPO, revealing plans to raise an estimated $75m (£51m) by listing on the Nasdaq. The company said in a statement that it had not yet determined the number of shares that will be issued or the price range, but reports said that it is expected to try to raise up to $75m. Zipcar confirmed in its SEC filing that it plans to use the proceeds from the IPO to "pay down certain indebtedness" and use any …