After playing Midnight Club: Los Angeles, for the past week, I have to agree with the GameSpot review: the races are very difficult. But that's just the initial impression.
Grind for a while, make some money to get your car tuned up well, and you will start winning races. You start with a small potential selection of cars--I chose the 1998 Nissan 240SX--and get to drive around Los Angeles looking for people to race. Prepare to watch the other cars streak past you at the starting line, and spend the race negotiating your way through traffic and around turns, following your competitors to the finish line. But after grinding like this for a while, you build up enough money to upgrade your car. Performance mods, like forced induction (turbo) and sway bars, are essential. Then you will find yourself winning maybe 25 to 50 percent of the time, which is still a long way from rewarding.
I found that freeway racers seemed to be the easiest to beat early on, even if they have a higher level of difficulty. After upgrading my Nissan, I built a big enough bank account to buy a muscle car, the 1987 Buick Grand National GNX. That one is very fast, but the handling is lousy, even with all the suspension upgrades available.
This car also proved a problem because of the bad controller mapping of the game. You use the right stick to accelerate by pushing forward. Push back for braking and reverse. So on the approach to a turn, you want to brake. But this car has a nitrous injector that, when spooled up, also gets activated by pulling back the right stick. Braking for a turn suddenly turns into a high speed excursion into a wall. Fortunately, there is a handbrake, but without careful application you'll be pointing in the direction you've just come from.
After a number of races in the Buick, and more in the Nissan, the game was getting addictive, and I built up enough money for a second-tier tuner car. I opted for the Pontiac Solstice, one of the few newer cars available. Stock, I was losing races right and left, but it didn't take along to get upgrades for this car, making it mostly competitive. Even with this Solstice, you can still hear yells of frustration from my house as I get into a nasty head-on collision or slide around a corner into a wall during a race.
Here is a video I made of one fairly easy race, putting my Solstic up against a VW on a canyon run in Midnight Club: Los Angeles. It's not the best driving, and the game looks much better on an HDTV.