I enhance my game play a bit differently, being a computer geek. I keep detailed spreadsheets of statistics on every car/race and constantly try to beat the last time. I even break the cars down by what mods they have on each race. Sometimes it takes me longer to add in all the stats then it did to run the race,
Also every car I buy or win I run through the same set of races and use a formula to rank each car. Not perfect because of all the variables (esp. tires), but a good indicator. (Tracks I use are 1/4 mile, test track, Ring and Cote)
As far as the actual races I always try to use a diferent car each time I run the same race. Sometimes that isn't possible, but 90% or so it is. That gives me more car stats and added challenges that you wouldn't get by always trying to use the "best" car for the race. (I restart the game often, because I like the start of the game better than the end).
Finally I always try for at least 30 a-spec point or more. But I am not yet to the point of a-spec point hunting that some are. <30 points usually makes a boring race...