Baffling Problem... please help!

HI -

I've got a problem that no one can figure out...

I've got a '98 M3/E36 Sedan. Recently went to put the same winter tires back on & the inside rim is rubbing on the calipers (fronts for sure, haven't check the rears). The rims were not scored from previous usage. Car was up on a rack at the time. Put the summer tires back on for now...

Here's a few other details:
winter: directional Dunlop winters over Borbet rims (I believe 16's)
summer: Mich P/S over stock M3 rims
upgraded to drilled/slotted rotors (still stock calipers) since the last time these winter tires were on (a few years ago/was garaged the last few winters)

Random ideas as to the cause (mechanic says no to each of these):
*If car is off the lift rack, will load on tires cause the whole hub assembly to shift caliper slightly, thereby giving clearance?
*Are drilled/high-performance rotors somehow causing calipers to rub?
*Can winter tires get out-of-round? It has been 5yrs since last installed.

One other thing we just discovered: One side of the Borbet rims are direct fit whereas the other side need hub rings, otherwise they are "floating" on the hub, held only by lugs. Any ideas if there is some reason for this?

PS - I bought this 98 in 02 & the car came with these snow rims & tires. I have used them before, with no probs. Just now discovered the direct fit issue.

Any ideas BMW experts? -Thanks!

Probably suspension related....How are the rear trailing arm bushings? Diff mounts?

Have you inspected the rear subframe?, they can crack over time...

Did they have spacers before?

And having two rims with hub rings and two without sounds like you were using some spacers.

Duh, there are VERY few 16" wheels that will clear the front calipers on the E36 M3. That's the problem.

OP stated he had these on the car previous to this so fitment at that time was not an issue.
I agree I don't know of many 16" wheels that will clear...