Hey Lloyd,
Do you lose connection at other times or only when you play this sim?
Its worth checking your cables from the phone point to the modem and then to the PC, do you use any other USB devices? wheel or pad KB, mouse ect? some gamepads can mess up things sometimes.
try to limit the amount of programs runnig in the background even MSN and media player can have an effect online, press ctrl-alt & Delete together and the taskmanager should come up then you can click the process tab and see whats runnning,
P2P is things like Kazzaa and Limewire music(and other files) sharing programs, AOL are probably using content filtering and could be slowing or even resetting your con form time to tme.
Ping times are shown ingame in the multiplayer connection list see pic below, what XXms times are you getting when you display the server list?
Is the modem in your house/flat/castle
connected to the master BT point? or is it connected to a secondary point? (the master is the first box the phone cable from the pole/ground connects into and normally has a horizontal split type front)
If you can try it in the master point (with the front half of the cover unscrewed as this temporarily disconnects all the secondary points)
if it works fine in the master your internal cabling could be faulty.
I think your problem could be either your PC's power supply not being able to run your PC + Modem + anything else you plug in. OR, your ISP/BT, maybe you are a great distance from exchange, OR faulty internal phone cables, OR, the modem you have is overheating (is it some 105 or 150 BT thing?)
It could of course be any number of things but thats all I can think of off the top of my head
SD.