I'm no Mario, and I'm lucky if I can get into 50k bonus land in most cases, but running the "near me" method is still good for business.
I run the first time out at a clip good enough to get a clean lap and a feel for the track with one of the new car dealer cars.
That puts me in the $2500 category most times. I then go back in and change rivals, X'ing to the top guys to see what the max class numbers are and the best times, then to the near me list to see where I'm ranked.
I then go build up a car for the event, tune it the way I like, save the tune and go back. I then run the same way as the first time, just hard enough to get a decent time, except this time I have a decent car under me and will end up in 10k/25k land after the first run. Once I'm in 25k land, I start driving. I'll run some extra laps then, not for time but for the XP for me and whatever car manufacturer I'm in, as I am slowly building 100% free parts affinities.
When I hit the 50k mark, I slow as much as I can to keep the times as close as possible. I eventually hit a wall where my disability prevents me from overcoming the time, and that's where it ends for that event.
The Drags are great for cash, the current Hock netted me 400k in a couple hours. I ended up somewhere in the 4,000th range. Same with the Dart in the previous drags. No real XP, but the cash is quick.
Any event in 25k/50k land is worthwhile, though longer tracks like Le Mans and the Ring can be a bit "counter productive". I happen to like them, and if you want quick affinity boosts with any manufacturer running there a few runs will get you free parts in no time.
I have to say coming from GT5 land, that this is by far one of the most interesting aspects of a driving game I've come across in a long time. It's grinding, but with purpose... As well as getting to to have some competition with a few club members. And it makes good money, as long as you're willing to run to earn it. No "Brie-Spec" Cheese or B-Spectacular money laundering schemes. I've run some of career mode, but not nearly as much as Rival mode.
The lap money for most events is decent, and Bounty money is gravy... And you don't have to be the greatest driver to make a good living at it either.
I do have one question, or gripe, and that's having to reload the car and setup each time. Is there something I'm missing that will let me just stay in the same car, or continue to the next rival without reloading it all again from the start...?