so i bought this game along with my xbox last december and have been playing career mode up until today (i do not play a lot of video games just when i have time). i am now stuck at 98% with a lamborghini murcialago and am not able to beat the game. it is the last boss race, i beat 2 out of the 3 races to win the game, but the last race is harder and the opponents car is much faster. i have to upgrade my car but i only have $1000 and races only bring me $700. i think i ran out of the rival races when driving in free roam which give $1000 each race. any hints or ides on what to do? it is really pissing me off.