Frontera 92 question.

Hi!

I have almost bought a car of the subject.
Is that year model´s body and/or panels zinked?
What is the "default" rost corrosion treatment from factory?

Have any of you guys "tuned up" a 2,4i Frontera?
How and what cost? I merely need a little extra punch for towing
thow don´t want to decrease fuel mileage...

Thanks!

Mika