Go to seasonal events tab.
Bonus race No. 4:
the VW event, all you need is a racing modified golf which will set you back 200k
Super Gt event, i bought the Nissan Yellow Hat YMS TOMICA GT-R 08 for 950,000cr but pocketed 1.5mCR with ease after winning the race.
Bonus race No. 5:
european touring car event: you should already have one from completing some of the races in A-spec mode, easy win making you 2m richer
TVR tuscan speed event: i already had a RM tuscan speed 6 and the race was incredibly easy
People i am by far not the best driver out there, so if i can do it you guys can do it even quicker than me