The 986 child seat deactivation schemes for the 986 and 987 are different in their approach for Porsche to extract an additional $400 to $600 from their customers with kids. The 986 method consisted of a deactivation bar mounted at the base of the passenger seat and the dealer with the PS2 would "re-program" the car to recognize that the deactivation bar was present. When the special belt at the base of the Porsche child seat (made by Britax) was inserted, the passenger air bags are deactivated (10 second airbag blink.) In the 986 days, if you bought the $400 dollar child seat package, the dealer would install it for "free."
I have seen elsewhere on the internet that people had fabricated their own special belt buckle but being a newbie to the Porsche scene at the time, I chose not to take any risks with the kiddie passenger.
The 987 approach requires the installation of the key operated deactivation switch on the passenger side of the dashboard. The passenger airbags are manually deactivated with this 987 approach. However, I believe this allows the use of any child seat available on the market (Although Porsche is pretty proud of its child seats in the Tequipment section of its website.) I think I read somewhere that the dealers charge $600 dollars for the 987 deactivation switch and installation.
Below is a screen capture from the
www.rennlist.com website showing the 986 child seat and deactivation bar (on sale!) Note the 996 part number.