basic upgrades:
-replace the air intake- AEM is a good brand
-change/replace the headers- DC sports....etc.
-change/replace the exhaust pipes...two or two and a quarter inch is good
-buy a quick shifter
-coil over springs
-cams
-upgrade the clutch
-spark plugs and spark plug wires
-and a lot...
Maybe you or someone accidentally spilled motor oil on the engine or on the exhaust manifold. When the engine warms up it burns or cooks the spilled oil and that's probably where the smell is coming from.
You're only 15 my friend, I think you should focus more on something else rather than worrying about your parents. I'm not saying that you should just ignore them, what i'm trying to tell you is that they're old enough already to know what is wrong and whats right. You worrying alone won't solve...