I want some extra HP and TRQ.Please help me any&all advice.

[SleepersBeatRice]

I own a 1999 Grand Marquis GS, it's 4.6 is running fantastic, infact the ENTIRE CAR IS IN FACTORY CONDITION! This was Garage kept, it has virtualy no rest. But now my CRY FOR HELP QUESTIONS:

Without any major MAJOR WORK, how could I give her more power WITHOUT risking any needing for a new tranny or supsension/steering componants? I know there are a variety of ways, modding the intake, chip, forced induction, replacment of originial equipment, but what is the best way to add more power for some one on a tight budget and not willing to completaly take things apart/out?

The plastic what ever it is thay says 4.6L that goes directly over the intake manifold and throttle, is it a "heat Sheild" or does it serve no purpose but to look nice?