Sorry to hear about your progress loss. I always back up my save to an usb stick once a week so I can't lose too much progress.
For grinding:
1. First set up the conroller with Motion Sensor Steering, Right Stick for accelerator and turn the vibration function off.
2. Garage > X-Bow R '12 > Traction Control 1 > All other aids off (ABS can stay) > Car Settings >115% power ratio and 91% weight (should be N300) > Front tyres Sports=Hard, Rear Tyres= Racing Super Soft
3. Arcade > Custom Race > Blue Moon Speedway (the first one) > whatever time it's on > Garage Cars and select your already set up X-Bow > Automatic
4. Race Type=Endurance > No. of Cars=2 > Boost=Off > Opponent Category=Gr.1 > Opponent Difficulty=Proffessional > All other settings are left alone.
At this stage you should have this screen below, but you can adjust the time to however long you want. You aren't going to win so we're looking at the second place values, 10min. pays 50,000, 4hrs pays 801,000, 5hrs pays 1,000,000 and so on.
View attachment 739951
5. Then press start race > put your rubber band on > set your controller on an angle so your car rides the wall (it might come off the wall breifly but that's ok) as in the pictures below.
View attachment 739975
View attachment 739976
It's probably a good idea to run a short race first, and even now I still check every now and then if I'm home. I've come back to my car either doing doughnuts or nosed up against the wall smoking the tyres
(this happened when I'd forgotten to put Traction Control on)
Happy Grinding