Fastlane Nissan 180SX Type X Is Impossible To Beat

I tried to do fastlane 180sx in vault events and at day 5,it's impossible to reach the required BP,i need to get improve kits (that boxes idk how they are called in english because i play the game in spanish) but i can't win any,there ain't replayable races to win them,and the races to win them is later the 529 BP race,im stuck at 510 BP and i can't get any more things to improve the car (i hAd to buy ECU kit to try but yet still there wasn't much dkfference) so yeh,it's impossible to beat unless you spend 50k in improve kits

Pd:i couldn't send all the screenshots but it's all like that