I was fine last night.
1. Make sure you are hardwired directly to your modem. No routers, no wireless. Before you start the game, reset the modem.
2. Sync your time and trophies.
3. Start the game, then disable any custom music.
4. Clear your system cache.
5. Save your game.
0 problems from 10p-4a, and remote racing before 10p CST US, with lobbies upto 12 people and voice chat disabled. Sucks, but it does help stability.