Has anyone been satisfied with the heat that's generated by the seat elements in the 960? I just had mine (seats) checked; they're 'performing within Volvo parameters'. But my bum doesn't get warm! Any ideas? Any 'aftermarket heating elements? I also have a Ford F150 pickup; it's heated seats get so hot I have to shut them off after about 10 minutes! Thanks in advance, Scott 1997 960 89,xxx miles