FSportIS

iTrader: (13)

If you care for fuel economy, you should get the IS250 or even CT haha.

IS350 is quite fast enough for street. I'm also surprised that you can hold the urge to go zzzzrooooommm with it.

P128sniper

As everyone said u are pretty good already. But to answer your question on what service you can perform to help it all depends if your behind on your service. Couple things that can help is changing your oil and oil filter, changing your spark plugs, changing your engine air filter, and possibly cleaning ur MAF sensor if it's dirty. I just had all those things done and it helped me some...