Stop with the bs ethomaz, you just can't do that. Play Forza 4 before you judge the difficulty. Seriously, is that too much to ask for?
If you don't use a car right at the upper limit of the performance classification, with AI on Hard, in a proper race, you have absolutly no clance of winning. Playing later races in Forza 4 without a car at the top end of the performance index is like wining races in GT5 without a Corvette ZR1, but several times harder.
I can say this because I've nearly beaten both games, you can't because you only played Forza for an hour or so at a friends house.
P.S. If seasonal events were such a huge focus of GT5, why are there no trophies associated with it? Maybe to you it's a huge part of the game, but when I had a working PS3, I didn't even notice the mode, and I bet out of all the people I know who play GT5, you're the only one who noticed this mode.
Also p.p.s. Before you go on again and say Forza 4 is easy, play the game on anything but intro levels. TRY, JUST TRY, to come close to my Top Gear Track time. If you can't even come close to my time, you can't tell me what's hard/easy.
I played the Forza 4 and it's easy... and the fact I can't beat your time in Top Gear track just prove the game is easy... I can be an amateur in sim racings and get first or second place in every race in Forza but I can't won over most of guys in online.
And Seasonal Events is pretty known by everything played GT5.
The Seasonal Events is even used for the GT Academy qualifiers... it is a extended Carrer mode... the Online Dealership Update just exists to you buy car to Seasonal Events.
Every time you talk about GT5 seems like you never played it... because you didn't race anything in the game... try to play the game again and have fun.
PS. Open GT5 now... play the event "New Year’s Holiday Challenge" and came here back to agree with me... you is just losing all the experience that GT5 can offer.