just leave it as stock =)
u can minor modify it, like drop in filtr, irrium spark plugs,
Front n rear UR bar, 15inch sport rims (change only when ur 14inch tayar botak),
always stick to fully syntactic engine oil. it wont cost you more than 3k.
the remaining 5k? spend it for food, shopping and entertainment =)
im driving a 1.3 flx too and im enjoying it at it's cost^^

monthly installment is very comfortable too as i got lots of spare money to go genting, go telok gong eat seafood, go melaka, penang, johor during my weekend.