Hybrid42

I own a E250 coupe Avantegarde that for tax reasons killed me but my wife gave it to me as a gift but now it has become a curse. The fuel quality required is 95 unleaded for the vehicle but we only get at best 89 to 92 on a good day and my car has detoriated to a point where the computer just constantly malfunctions and the after sales service here is non-existent. Am at my wits end and need help on what to do ...