Here's what I know. Starting with the 2006 987 (the 2005 did not have it) Porsche started putting in smart air bag technology for the passanger seat. It senses automatically if the passanger weights over 90 pounds (approx.). If under the 90 pounds, air bags are off.
So with my 2006 when I got my car, my daughters at the time were about 4.5 and 2.5 years old. I was using "booster seats" at the time (check State laws for your area regarding a 2-seater car). So all I had to do was put a thick towel on the leather seat, plunk down the booster seat, and strap in either daughter.
Don't know if this will help you (but it will tell you if your wife weights over 90 pounds!
) now, but in a couple years it may come in handy.
This upgrade Porsche did, saved me over $1,200 when I bought my car vs a 2005 MY since I did not need the special Porsche child seat and programming charges.