Do you have experience removing the front seats?
I"ve removed the seats from my '88 Audi 90 and it was relatively
painless, albeit they were not power adj. but they were heated.

I'm also considering replacing the seats with something like a couple
buckets from Sparco, I'm not sure if you use a mounting bracket or
just to the floor. hmmmmm.

Evidently not true... see below...From an old post by one of the
experts...

Absolutely!  But, in the interest of not getting into undue
complications, swap the whole seat.  You'd have to pull them out to
get the backs off anyway.

Each is held in by 4 Big Damn (TM) bolts (17mm, IIRC) and, if they're
power or heated, two or three connectors (be aware of the knee bolster
connector up under the front if these are 'is' sport seats)
underneath.
Start with the front ones and LEAVE THE CONNECTORS POWERED UNTIL YOU
GET ALL THE TRACK BOLTS OUT!  You need to run the seats forward and
back to
get access to them.  You also need to remove the outer belt fittings
(also 17mm, IIRC) before you remove the seat from the car.  Easiest
with the seats full forward, IIRC.  Be careful to note where the
washers are on these.

After you have them out, flip them over and simply swap the tracks (4;
maybe 6 more bolts, each, IIRC - and 10mm or 13mm, off the top of my
head).  If you have power and/or heat, be careful of the wire routing
and wire ties.  Just cut them off and replace them.  It's easier to
replace the seat belt buckles while they're out.  Reverse to install.

I've done this with bottom-of-the-line '82 E28 seats as well as with
the latest 'is' sport seats.  The additional gee-gaws on the 'is'
seats take
a little more time, but it's not difficult.  I didn't bother to move
the knee bolster switches back to the outside, so they're by the
driveshaft
tunnel now; at least the one that wasn't already broken off is.
Probably take you about an hour of leisurely work with average hand
tools.
--
C.R. Krieger
"Don't argue with 'em, dear; they're beneath our dignity." - W.C.
Fields

As someone else has pointed out, you're flat wrong.  I've *done it*
and the procedure was posted in that answer.

For an E28, it's actually quite likely they *would* sell 'em.  There
just aren't that many of us out looking for those parts any more.  As
for the tracks, I'd almost bet that regular non-sport power seat
tracks would be identical.  In fact, if you're looking for a
ruthlessly *practical* solution, I'd bet even the manual adjusting
tracks from an older or 'lesser' (528e) E28 would work.  Find yourself
a car with a torn-up seat in it and offer to buy the whole seat
(because they won't be able to sell it that way).

IIRC, that's the way they go together.  To do the side-to-side swap,
you need to unbolt them from the tracks and you then have a
flat-bottomed seat on your hands.  I do *not* remember if the seat
tracks appeared interchangeable in any way, but the whole thing isn't
all that hard to take apart.  Unbolt things (don't forget to *unplug*
things, too!) and take a look.  It's best to run the seatback up as
vertical as it will go and then unbolt the seatbelt stuff while it's
in the car.  *Keep it connected* to run it forward and back on the
track as needed to access the floor bolts.  It isn't rocket science;
and these fasteners, while tight, are rarely rusty or seized.

Good luck.  Or, by this weekend, you could buy one of mine (starting
late tonight):

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2471244764&rd=1
--
C.R. Krieger
(Gettin' a red one!)