Audi A8 Aitbag ( again )

Hello,
I had already posted about my airbag problem. get when heavy people have sat on the seat the message "resistance sporadic too high" and the airbag lamp lights up. I have already worked with kontaktsprey on the connectors, which apparently did not help. Now I'm thinking about replacing the contact mats. this shows a residual value over the entire area that is evaluated by the airbag computer. So no simple contact switch. for these mats the audio haendlier wants to have about 270 euro the stueck, affected are the co-drivers matte and the behind the driver. has someone a source of reference for this ? I could not yet break the dinger apart to get the part numbers, it is an 11/98 he A8 with electric sitting front and rear.

gruss Stefan