I just got it about 30 minutes ago. I had 7:29:303 earlier today which ticked me off. I had a few 7:31.xxx's, and about 4 7:32.xxx's
Here was my strategy
1. Practice without SRF to learn the track
2. ASM=OFF, ABS = 1, Traction control 2 or 3
3. If you can do it without the driving line, that's better. The reason why is that there are several 'S' curves where the driving line has you braking heavily and you don't need to if you do it right. There are several turn combinations where you don't need to brake at all or very little if you set your car at the optimum angle going into the turn combo. I left it up there as a memory jogger, but for over 90% of the course I ignored it or it reminded me NOT to do what they suggest. Practicing will get you learn these shortcuts.
4. You can go halfway over the curbing/onto grass on the inside of the turn to get a better inside line
5. In the outside of a curve you can go completely onto the grass, but watch out because sometimes that may lead to another curve where you'll be on the inside and you're time will get invalidated (time will turn red). Plus if you hit a wall or go onto sand it will drastically slow you down.
6. After you feel you've learned the course well, turn on the SRF and it should be much much easier. You can do substantially less braking and skid around some of the curves or it will get you pointed in the right direction for the next turn or straight away.
7. The ghost car can help if you're trying to gauge how fast you are going, but it can be nerve racking if it's in your face and you are trying to concentrate on the turns, so you want to get ahead of it. Later when I was getting close to the target time it was annoying me so I'd back out to the main arcade menu and then go back in to get rid of the ghost. You'll learn what the good time splits are at certain points in the track (i.e. I knew I was doing good if I was around 4:02-ish just before the sharp right hander that leads up to the carousel).
8. Another good way to train for this is the AMG Driving School special event.
My hats off to the people who say this is 'easy' and can destroy the time without SRF. Some people love Nurburgring, but it's far from my favorite (Tokyo 246).
