My money is on the DP1, but my second 'guess' would be a Radical. Speculation won't get us very far though, we shall just have to wait. The fact that one person owns the licence to two things doesn't mean LFS was granted to include both things in LFS.
Get S2. You can start learning some of the tracks and cars, although it's likely that the tyre physics update will change how the cars respond anyway. When S3 comes out you can buy that, and thus pay in smaller 'chunks' making it easier to hide from your mother/girlfriend/boyfriend/bank manager.
And the worrd you're looking for is "to". To S2 or not to S2. 2 is a number, and is inapproriate.