The Cayman has a few idiosyncrasies that might not be familiar to first time Porsche owners. Like them or not “they are what they are” and knowing about them in advance of a problem may help some of us out of a jam.
Air Compressor - If you ever have to use the tire air compressor Porsche really means it when they tell us to plug it in cigarette lighter outlet. Otherwise plugging into the 12v outlet will blow the fuse.
Battery – Due to the many electronics that draw on the battery it has a high probability of discharging if not driven for an extended period (or if a maintainer is not used). If the battery goes dead to gain access to the front compartment where the battery is you will need to use the procedures on page 234 of the manual “Emergency unlocking of the front luggage compartment lid” If the battery is discharged, the lid can be opened only with the aid of a donor battery or charger. Familiarizing yourself with this unusual method in advance is a good idea.
Brake Noise / Sticking Brakes - If after washing or in wet humid weather the car is left overnight with the parking brake applied the pads may become stuck to the rotors. You may hear some scraping noises the first few times the brakes are applied and is the pads scrubbing off the rust on the rotors. This is normal but can be avoided by driving enough to heat up and dry the pads before parking overnight.
Bulbs - The factory foglight bulbs are H11 (manual says H8) and an H6W (manual says W5W)for the "driving light" or "parking light".
Cup Holders – To lock the cup holders into place and prevent unnecessary movement, return the center portion of the cup holder bar to a closed position after extending either or both cupholders
Gas Filler Emergency Unlock - There is a manual release for the fuel door in the passenger door (in a left hand drive car) near the the hinge.
Hood Alignment - On all Porsches, including the Cayman, the hood's leading edge is designed to be slightly lower than the bumper cover.
Ignition key/ignition lock - Do not insert the ignition key into the ignition lock if the vehicle battery is discharged (look at the interior light for a clue). The ignition key can no longer be removed. The key cannot be removed until the vehicle electrical system is supplied with power again.
Update: MY08 Owner's Manual emergency key removal procedure:
1. Open the fuse box and unclip a metal hook on the inside of the cover.
2. Use the hook to remove a plastic lid on the ignition lock to the right of the key.
3. Turn the ignition key counter-clockwise as far as it will go.
4. Press the metal hook into the opening and turn the key to its intial position and remove it.
Lane Changer - To indicate your intention when changing lanes, slightly depress the signal lever to the resistance point. The lever will return to the OFF position after three blinks of the signal light which indicates your lane change direction.
Noise when Reversing - If the steering wheel is close to or all the way to the steering lock the power steering pump may push against the lock and make a “clunking” noise which is normal. This can also be exacerbated by cold weather making the tires less pliable.
Oil Level - There is no dip stick. Oil measurement is done via a computer reading. The best time to check oil levels is the first thing in the morning before the car has been run when the wait time is under six seconds. Be sure to check the measurement when the car is parked on a level surface.
Parking Lights -Like other European cars the left and right parking lights can be turned on individually by moving the turn signal up or down and turning off the engine (page 124). This is sometimes done inadvertently.
Passenger Air Bag warning – Not in the manual but a common problem at least on ’06 models due to moving the passenger seat too far to the rear (other airbag information is contained in pages 42-48 of the 2006 US owners' manual)
Rear Fog Light - You only have one (on the left side). Some people think that the one on the right is malfunctioning.
Remote Key - The remote-control standby function switches off after 7 days
If the vehicle is not started or unlocked with the remote control within five days, the remote control standby function is switched off (to prevent discharging of the car battery).
1. In this case, unlock the driver’s door with the key at the door lock.
Leave the door closed in order to prevent the alarm system from being triggered.
2. Press button 1 on the remote control. The remote control is now activated again.
Smell - The cars are protected with Cosmoline for shipping and delivery. It will burn off over time but there will be a distinct smell that will be observed during that time.
Smoke - A puff of smoke on start up is normal. Usually this occurs after a period of inactivity. The flat six in your car collects a little oil in the bottom of the cylinders when they sit, and this is what's blowing out when you first start the motor.
Sockets -The sockets and thus the connected electrical accessories function even if the ignition is switched off or the ignition key is withdrawn. If the engine is not running and the accessories are switched on, the vehicle battery will be discharged. Do not operate additional accessories for more than 5 minutes when engine is off. (Page 140 of '06 manual)
Stall/Start - After stalls turn the key all the way to the LEFT (counterclockwise) before restarting.
Tires/Tyres – There is no spare. Reading the instructions that start on page 224 of the manual and locating the tire sealant and electric pump ahead of the need to use it will save you a lot of tears later. One mistake some make is to pull the offending object that caused the flat out of the tire and then attempting to seal it. You also don’t have a flashlight/torch so that means flats will occur at night
unless you come prepared. Porsche says that "tire repairs are not permissible under any circumstances" (page 103).
Tires/Tyres - Use only plastic valve caps per the manual (page 210 of the '06 version).
Winter Tires/Tyres – Porsche recommends fitting winter tires where temperatures drop below 45 degrees (7C).
Until 
