I feel your pain man. I've done all the events but I'm going back to perfect each one and complete the challenge sheets. I've also managed to get gold with a great rating giving me 4 stars. It's not funny, is it?
The secret is to simply keep glancing at your rating when you can. Keep up the oncoming, drift, near misses and boost going. Short cuts can be detrimental sometimes. If you use too many that you can't drift in or get oncoming in, it can be hard to get Awesome in those circumstances.
If you want to know how I've done so many so far: Go through the track once or twice without boosting or without trying to get the fastest time. Learn the track layout, look for shortcuts and learn the traffic patterns. When you think you know where you're going and have planned the best route, give it some wellie and go for gold. Even if you crash, keep going. Look at your final time and try to work out if you think you would have made it if you take 5 or 6 seconds off for each crash. If you think you would, then just keep going at it. Each time you crash, pause and restart. It's frustrating, but the feeling of reward when you finally do it, is well worth it. I saved a clip of crossing the line in a burning lap with less than .1 of a second to go. That was a pant threatening moment.
Of course, when you've tried 20 times, you're going to make it this time and crash into a bus 20 feet from the finish line, well, that's a different set of emotions all together. Damn wireless controllers. At least when you threw a wired controller, it's damage distance was limited. Wireless controllers can go for miles. It turns out MS not only hit on an ergonomic champion there but also somewhat of an aerodynamic one...
Good luck with the golds. Let us know when you've perfected them all.