Our approach to the development of retrofittable air conditioning systems for the Maserati double ignition models 3500GT/GTi, SEBRING, MISTRAL followed the goal of developing a system that (1) can be retrofitted without intervention/changes to the vehicle substance (body, etc.), (2) visually appears as little as possible; ie. is not really visible and (3) can be installed as easily as possible. The availabilty of modern, small but highly efficient components such as compressors, fan motors, etc. are the basis of our systems.