Harry Wilson, who was a member of the government-appointed task force, notified the Detroit automaker on Monday that he wanted it to spend $8 billion to buy back shares, and that he will nominate himself for election to the board of directors this spring. GM, which has 13 people on its board, disclosed the letter on Tuesday. In an interview with Reuters later on Tuesday, he said GM’s management was too slow to make changes to improve profit and too vague in setting near-term milestones for performance. GM shares closed up 4.2 percent at $37.52 on Tuesday.