I've taught myself to read a little bit of German over the years. But there're a lot of slang type words that simply defy normal translation means. I found this list that is very helpful when searching for Porsche items on German eBay!
6-speed = 6-gang
Accessories = Zubehör
Accident-free = Unfallfrei
Air Conditioning = Klimaanlage, Klima
Air pressure = Luftdruck
Alarm system = Alarmanlage
Armrest = Armauflage
Automobile = PKW
Bumper = Stossfänger
Bumper apron//cover (front) = Stoßstange, Frontschürze
Brakes = Bremsen
Brake disks = Bremsscheiben
Brake pads = Bremsbelägen
CD Changer = CD Wechsler
Convertible (Vert) = Cabriolet, Cabrio
Corporation (Corp.) = Aktiengesellschaft (AG)
Cruise control = Tempomat
CSL diffuser = Heckdiffuser, Heckschürze
CSL trunk = Kofferraumdecke (mit integral Heckspoiler)
CSL roof = Carbondach
DOT = TÜV (same function, different national standards)
DSC = Stabilitätskontrolle
Door = Tür
Engine air intake = Motoransaugluftöffnung
Exhaust = Auspuff, Abgasanlage
Fog lights = Nebelscheinwerfer
Front (as in wheels) = Vorne
Gasoline = Benzin
Headlight = Scheinwerfer
Headlight washers = Scheinwerferwaschanlage
Hood (Bonnet) = Motorhaube
HP = PS (Note: HP is SAE, PS is DIN)
Key = Schlüssel
Leather = Leder
Left = Links
Lightweight construction = Leichtbau
LLC = GmbH
Mirror, inside = Innenspiegel
Mirrors, outside = Außenspiegel
Nappa leather = Nappaleder
Oil = Öl
Paint = Lack
Park Assist = Einparkhilfe
Photos = Bilder or Fotos
Racecar = Rennwagen
Rain sensor = Regensensor
Rear (as in wheels) = Hinten
Right = Rechte
Seats = Sitze
Seat-back width adjustment = Lehnenbreitenverstellung
Seat heater = Sitzheizung
Sedan (Saloon) = Limousine
Service book = Scheckheft
Sequential Manual Gearbox = Sequentzielles ///M-Getriebe
Spare parts = Ersatzteile
Speed limiter removed/open = V/Max offen
Spoiler (wing) = Heckspoiler, Heckklappe
Steering wheel = Lenkrad
Sunroof = Schiebedach
Suspension = Fahrwerk
Switch = Schalter
Tax (VAT) = MwSt. (nearly 20%!!)
Tires = Reifen
Transmission = Getriebe
Truck = LKW
Trunk (Boot) lid = Kofferraumdecke
Wheel size (inches) - Zoll (as in, 19 Zoll Felgen)
Wheels = Felgen
Windshield = Frontscheibe
Xenon headlights = Xenonscheinwerfer
Note: in German, "ss" may be substituted for the etset (ß) character. Also, any vowel with an umlaut (ä, ö, ü), may be properly spelled by omitting the dots and adding an "e" behind the previously-accented letter (ä = ae).