hi, my WRX is 2003 and has 77K mileage. there are just few things I want to ask:

1. Can I just put in regular gas instead of premium, and just change my oil filter more often? (i am a stundent at a private art school, so i have no dinero..)

2. I never owned a car with a turbo, so i was wondering if it is normal that my car is pretty warm after I drive to some place? ( like, it is a lot hotter than say, my dad's Lexus GS300)

3. One of my friend told me that i should spray water into the hood scoop, into the intercooler after I drive. I said it would stretch and crack the metal pieces under the hood, but would it really help/harm my car?

4. Is the 3rd gear notorious for grinding/mismatching? Should I check it out while I have a warranty on the car? But I`m still practicing manual, so...

BTW, even though the fit and finish isnt great on my car, i LOVE my car.. I want to keep it running for a long time. thanks for taking your time and answering my questions!