I see stock mounts are near $100 each, and companies like AKG do not offer mounts for the 318 E30 models. Any poly or "upgrade" motor mounts available? Thanks.
You've probably heard of Vorshlag, and we make tons of BMW motor and trans mounts. Now you can choose Vorshlag Competition Motor Mounts for the E30 M42.

We have custom made a number of these over the years for the E30 M42, including several iterations for our own 1991 E30 M42 that we raced in SCCA autocrossing (STS) as well as NASA TT/HPDE track use. We made these poly mounts for the engine and transmission because the stock mounts were SO WEAK. The transmission mounts once stretched under hard cornering, allowing the transmission to shift sideways by almost an inch, causing the shifter to bind up which resulted in a high rpm "money shift". Luckily, only the clutch exploded...
Left: Stretched OEM rubber mounts after the "money shift" incident. Right: exploded clutchThe difference in throttle response and especially
shift feel after going from OEM rubber to real poly engine + trans mounts in these cars is
dramatic. The M42 motor isn't known for its smoothness (compared to the BMW 6 cylinder) so there will be more vibrations transmitted into the cabin with racing style poly mounts, but the payoff is substantial for racers or dual purpose street/race E30s. We went through a few variations and durometer polyurethane inserts and came up with these 70A durometer "thru-bolt" style M42 mounts. Again, there is
some added NVH with this poly insert (if there wasn't any the mounts wouldn't be stiff enough to improve shift feel so much), but much less than the solid Nylon or firmer 95A and 85A inserts we tested previously.

We have made a number of these M42 motor mounts to order but have sold enough now to warrant a
product entry on our website. These are not volume sellers like our other BMW mounts, so we still only make them to order, which is why the cost more and take a few days before they ship (I have make each set myself, and its a pain).
Left: The 70A mounts in our E30 M42. Right: The 80A poly trans mounts on the same carBeing a bolt-thru design these also cannot fail from delamination, as happens with so many bonded motor or transmission mounts.
Cheers,