I had the side bolsters done on my e30 in in the oem color cardinal red. My upholstery guy was able to buy the leather from Germany that matched in color and texture. The leather was the same as BMW used I was told. I had to purchase half a hide, but that only cost about $700 and I had enough to do the entire two seats. If you get a good shop it will look factory. I have the same problem on my x5 and will do the same some day.