They are symmetrical, it's the subframes that aren't (I think!)
Don't mean to pi$$ on your chips, so to speak, but the seats are not symmetrical. That's a passenger seat and it won't sit properly on the driver's side. Of course you might know this already.
I got a pair of these seats off ebay for £145 recently and now have them fitted in my 182. I put a few pics and pointers to fitting in a thread a while back.