When an S.E.C. Inquiry Is an Executive's Fondest Desire
National Auto Credit Inc chief executive Allen D Rice welcomes Securities and Exchange Commission's probe into company's earnings; investigation, and related one by Justice Department, probably represents Rice's best chance of keeping his job; Rice is in battle with company's majority shareholder, Sam J Frankino, who was not consulted on Rice's employment; Frankino is battling in Delaware courts to take control of the board; Frankino, who stepped down as chairman in March 1998, could face lawsuit by his hand-picked board; company says restated financial results show about $100 million in losses that should have been reported by Frankino; Frankino denies any wrongdoing; graph (M)
