Complex sentence: Not too much happened in the race until towards the end rain hit causing some drivers to spin off, even Michael Schumacher had an off but managed to continue and maintained his big lead, but he did not pit for wet tyres.
Split into simpler sentences: Not too much happened in the race until towards the end when rain hit, causing some drivers to spin off. Even Michael Schumacher had an off but managed to continue and maintained his big lead, but he did not pit for wet tyres.