hi i'm new to the tuner scene and trying to figure out what type of car to get any ideas would be a great help but i need a 4 door and looking for something under 25,000 just for the car.  

Is this your first car ever or just you first tuner?  

read the new car sticky.  for that price you could probably get an used buy eye WRX  

no its not my first car before i used to be into trucks and going off road but with gas prices i'm starting to get into the tuner scene  

what do you all think about the sentra se-r  

The SE-R probably isn't your best bet.

As k20 stated you should look into a used impreza WRX, or a mitsubishi lancer evolution, both AWD with plenty of power and room for improvement.

A used lexus gs 400 is good if you want something rear wheel drive.  

^ i'd go the IS300 route for a lexus  

what about an 08 mazda 3 for a place to start whats better a manual or auto  

^ unless your talking about the Mazda SPEED3 then i hope you're joking.  Manual will always be the best route unless you have an auto designed for racing like the ones in Lamborghini Murcielago's (spelling?).  If you have $25,000 to spend, and you're interested in getting a new car look up the new Cobalt SS Turbo.  260whp, runs 13's stock, and has better skid pad results than any FWD car ever made.  Even better its going for about $24,000.  If you prefer RWD then get an used SK2, and if you prefer AWD get an used WRX.  

i like the cobalt but they only make it in a 2 door and not the four door  

maybe a hyundai tiburon?
they look sweet i think and u can save a few bucks for aftermarket parts  

anyone know where i can find aftermarket parts for the 08 chevy cobalt ss/tc  

^ www.wesellcarparts.com   they're a sponsor on another forum i go onto and they have great prices and a broad selection.