good luck on the BoxsterS search. Its a very good time to be a buyer for this car. Most guys who ask me about the car can't believe you find a good at least 2000 year S model at $30K or less. They assume its a much more expensive car.
As for detailing well it all depends on what you do with your car. But first let me say CLAY BAR THE CAR! Most people rarely do this, big mistake. Even 15 minutes with the clay will triple your results. You can wash 3x's and there's still crap on your paint you don't see that dulls the finish. And using 1st rate towels will reduce the dreaded swirls. Try Poorboys or
Detail City for MF towels with silk binding.
If the car is just a cruiser that sits mainly in your garage well then I wouldn't be opposed to using more expensive time consuming products like Zaino and Menzerna see below
Menzerna FMJ
http://www.properautocare.com/menzerna.html
If you get the car dirty often then something cheaper/quicker with similar results is in order like Finish Kare, Optimum and Duragloss.
FK Gallery
Finish Kare
For garage queens the Zaino and Menzerma lines are excellent. Zaino has the best durability from what I hear so its a good choice for a car that's outside allot and you don't detail often.
I'm not a fan of buying all my products from the same company. I like to use the best polish, the easiest sealant, etc. Just a personal approach taste thing.
Zaino doesn't like being mixed with other non-zaino products so that doesn't square with my approach. Also, I wasn't impressed with the fact that you had to call long distance to get product information. Their lineup can be confusing so I think a 1-800 is in order.
I break down the detailing products into two categories:
seasonal care and weekly care.
For seasonal care I like Klasse All in One Polish after a good swirl removal with
Poorboys (start with the least abbrasive formula and work up until swirl are gone).
Poorboys SSR 2.5 swirl buster
To seal the deswirling and polishing I'm using Werkstatt Acrylic Jett, very very easy. Poorboys EXP is also easy.
For weekly after the wash care, I've become a big fan of the Finish Kare line up.
The stuff is mass produced for the boat and auto industry. They have a very 'scientific approach' that centers on paint decontamination and dust repellents. They claim frequent use of their product will keep the car cleaner, slicker, longer. After looking at my car this morning (it rained last night) I'm 100% sold. I use their cleaning detailer FK 146 and their magic 425 "teflon" liquid.
Their sealing glaze FX100 like 425 is unique in the industry, it will seal any type of product either bio like pure Brazilian Carnauba (s100, souveran, etc) or a synthetic spray gloss.
For a monthly paste wax I like Poorboy's Natty's (or Natty's blue for dark colors) or FK Pink Wax. For weekly wax boosting Duragloss Aqua Wax at $7 is the best bang for the buck by far.
http://www.duragloss.com/product.asp?pid=272
on the interior I only use
Einzett or 1z. Their leather care is the best I've used.
Their dash spray "Rubber and Vinyl Care" is the only product that touches my dash and plastic (topped with FK 425 for dust repelling). If you don't live in CA I also use Klass VLRP on anything that's black and plastic. Makes it look new.
On tires I like the Michelin tire dressing which you can get at pepboys or other over the counter places.