welcome to autopia and congrag on ur new roush.
i was gonna buy the roush until i saw the saleen speedester but with the roush stage three it will be hard to choose 365hp.
now like luster said clay then zaino but if thier are swirl mark from the dealer wash for example then use #9 other wise skip and since ur car is black i would highly recommend souveran or s100/ps21 the depth that these carnuba will give is the missing link in the zaino.other choice that i experiment is poorboy EX i found having 3 layer of zaino then 2 layer of EX give me the protaction and shine i was looking for.
search in the gallery for luster or amp99 pictures they both have black car which will give you the idea of which look you like.
as for the leather if it was the stock ford like mine then it's vinyl and the inserts are leather that's why it won't suck all the conditioner and they tend to crack fast if kept uncondition espacially the side.
if it was the roush seats then it will be a good idea to contact roush or classic soft trim since they are the manufacture of the seats if i recall and you can find them inthe internate.
good luck