Yes there is!
If he is (and appears to be) looking for a 6-pot, then check, double check, and triple check the rear subframe, specifically the rear mounting points under the boot carpet, they had a tendency to rip off the chassis on earlier cars.
Check the cooling system (and therefore the cabin heating), make sure you get to start the car from cold and check what kind of emissions are coming from the exhaust (white smoke = bad). The cooling systems are built by what can only be the German equivalent to Mr Magoo, with the aid of his mentally challenged sidekick, and as a result fail, lots. When the cooling system does fail, it only takes a few minutes of not noticing the temp needle rocketing to do head damage.
If there is a sunroof, check that it opens and closes properly, and that it is water tight, the seals tend to rot away and become porous. Damp headlining is a giveaway, or if it's dried out, it should feel softer than it's surrounding lining that never got damp.
If it's got one of the more feature rich OBCs, then check that all it's functions work, specifically RANGE and CONSUM1/CONSUM2. If part of the OBC appears dim, it's only a small bulb, not usually an LCD failure, so that's ok.
Listen out for clunking from the suspension, droplinks and trailing arm bushes are common failure points, in fact unless you can prove that it's had a suspension refresh, I'd be factoring in the fact that it'll be needing a full set of bushes all round at a bear minimum (probably needing shock absorbers also).
I'm also yet to come across an early e36 that doesn't have "quirks" with it's RCL/alarm. Mine had the great habit of only unlocking 3 of the doors, but happily locking all 4. It also liked to sound the alarm quite frequently, so I unplugged it. Muffin's also does this and was unplugged by the previous owner.
Other than that just check everything you'd check on any other car, electrics, dodgy noises from the engine bay, knocks, rattles, etc etc.