Take a few days off and go through the archives. All these topics have been discussed.

Shifting - check that there's a vacuum hose attached to the modulator on the driver side of the transmission.

AC - don't allow anyone to convert your AC system to R134a. Don't believe anyone who tells you recharging with R12 is illegal.

Cruise - try resoldering the joints in the cruise control unit.

Sixto
95 S420
87 300SDL