Since buying GT5 I have found about 2 maybe 3 lobbys where the racing was at an acceptable level, GT5 is a sim and yet you have so many noobs trying to win the race at the first corner or using you as there breaks.
I hate to say it, but most of the better (read cleaner) drivers are probably in private rooms. I've played GT5 for many, many hours online but the only time I've wandered into the public area was to randomly spectate on a few races--something I still do from time to. After what I saw, maybe only 10% of the lobbies I looked at had truly clean, quality racing. Public lobbies are very much a battlefield and I just can't be bothered. And I'm not alone in thinking this. What goes on there is pure 'gaming' and very little to do with real racing.
Over the years, across a wide spectrum of racing games, I've pretty much filled my PSN friend list to capacity with quality, fair racers. And few of them wander into public lobbies anymore either. The only public lobbies I would consider joining are:
1. Rooms with VERY tightly controlled filters. HP/weight/tires and NO assists. Especially skid recovery.
2. Shuffle races.
3. Rooms where I see at least 1 or more people I know. Because the people I normally race with wouldn't put up with baloney.
Of course, it's easy to argue that I never would have ended up with a full PSN friend list if I never played in public lobbies and met up with these people in the first place. And that's true. We all have to start somewhere. But I have no desire to go back where I started.
My best suggestion, if you haven't already done so is to run the GTP qualifier. (Well, it just ended but I'm sure they'll be another one). Then you can enter official GTP events where clean racing is strictly enforced. Once you take part in a few events, your PSN friend list will likely fill up pretty quickly.