Yeah, like spec r said. Get an allignment and good tires. If you live where snow etc happen look into all season tires. A tire I can suggest are look into some Toyo Proxe 4's. Thats what I use. Love them. Now if your tires are decent & you want some xtra preformance with your $900. Look into a cat back exhaust & intake. Now as far as this do you care about quality. If you do look into a Apexi WS2 exhaust. Not loud nor raspy sound. You can get 1 for around 400-450. Also you can get a short ram intake by AEM or Injen or even cheper mod. Go to autozone, pepboys & order a K & N slip in filter no more than 50 bucks. You can keep your oem intake. Another thing you can do by looking around for prices is since its an LS. Get a B16 head & have a shop install it because its a few things you have to do but I cant help on that part because never done a LS Vtec before.

Good Luck.. Post a pic. of your ride.
Hope this helps some