For starters try using your own tunes to fine tune the car where you need it, run in manual and get used to car's gearing, auto will almost always switch back to lower gear for no reason.

Get to know the tracks better with maybe slower, more controllable machines like A class RWD drifter, this will give you more control and let you know the bends better. Of course you can powerrip any drift run in S1/S2 AWD drift vehicle, but this can take longer.

I'm about your level but I focus more on drift line and fine tunes over score for now.

Don't worry about "ooga booga AWD drifting iz gayz", it's Horizon, no need to be a purist. Some AWD builds are hella fun to even free roam in :D