^^^^that. I read many reviews of positive performance advancements, from such tuning. my v8 disco does really well......downhill IMO, better to enjoy it for what it is.
body panels are a mixture of AI and steel. you can treat the undercarriage with one of several different products, to prevent rust.
I did the facelift... do not really like it (kind of dainty-looking) If I did it again, I'd opt out of that and leave the glass.