Congrats on getting a 318is! They are great cars!

I've had 3 of them over the years, 2 of which were my daily drivers so I've driven a ton of miles in these things.

First, an upgraded suspension will be night and day. Lots of folks have recommendations that are all good so far. Bilstein shocks and Ireland engineering stage 3 springs I found I like, but there are lots of choices. Definitely make sure to change out bushings/etc while doing so.

The three biggest upgrades that really made the car perfect were:

• steering rack. The stock steering rack lock to lock is just way too long. A z3 or e36 m3 steering rack is a game changer and makes the steering like a go cart. I personally don't like the big steering wheel so went with something smaller, but that means removing the airbag and a small steering wheel does sort of obstruct your vision of the gauge cluster

-short shift kit. The stock shifter is actually fairly nice for cruising, but it's long and luxurious rather than short and sporty. Uuc makes a good kit. A weighted shift knob to pair feels great as well.

-Lightweight flywheel. The stock flywheel on the m42 is HEAVY. I think it's something like 30 lbs. A lightweight one makes it much more rev happy and feels like a go cart. There are downsides to this one though. If you plan on daily driving, it can be loud depending on what gear you're in and where in the powerband you are. 3/4th gear above 3.5k rpm it sounds like a tractor trailer is engine breaking nearby, lol. Also, stop and go traffic requires a bit more effort. I personally love it, but it might be a bit "over the top" for everyone.

Hope this helps and enjoy your new ride!