1. Sport Soft Tires would be S3
2. There is the BMW McLaren F1 GTR Race Car, available on day 47* for 2,000,000, Not Shareable, Tradeable, 1 color. There is also the Mercedes-Benz SLR McLaren, available on day 17* for 610,000, Not Shareable, Tradeable, 2 colors (plus one special color for EU accounts).
The McLaren F1 in the game is a race car based on the road-going supercar, not the Formula 1 car.
* Day available is for players who's first car was the GTI