Advice on early 80s 320i purchase

I'm looking at buying a 82 or 83 320i. I'd appreciate advice from knowledgeable BMW enthusiasts:

1. Rust. Where to look for it and how prevelent was it in these models?
2. Bosche K injection. How reliable. How easy to fix. Parts availability.
3. What are some of the mechanical weaknesses of that model.
4. Any other advice to a prospective buyer.

I'm very knowledgable mechanically, but don't have a background in BMWs.

glad to hear someone else appreciates these fine rides...unless you really want an '82 or '83 for some particular reason, try looking at the earlier '78-to '80 models, as these came with the more desirable 2.0 liter engine, while '81 up came with a a 1.8l, with far fewer performance upgrades...you can upgrade a 1.8 engine, but at much greater expense...rust?the big places i'd look in particular are floorboards, rear shock towers, and the spare tire well in the trunk as particularly prone areas...hope this helps

I bought one of my kids an 80 320i about a year ago for one of my kids to drive to high school. 200,000 original miles from original owner, who changed oil 100 times (every 2000 miles). The engine is in fine shape but I told my son to change it every 90 days, closer to 3000 miles. Paid $1300 because of solid shape and six inches of services records and invoices.

Previous owner put in Bilstein shocks, Eclipse stereo, etc. so car was in good functioning shape.
Orange paint thrashed and a bit of rust at inside trunk lip by rear window and one lower rear door edge - simple and cheap to fix if he ever gets around to repainting.

A few weeks after we got it I noticed a "siren" sound like an old MG as he drove away. I suggested he check the trans oil level but he didn't and blew the five speec a few weeks later. A good used trans was $1100 installed, no clutch required and the car has been fine since then.

My BMW tech friends advised against larger rims and tires as the car was not designed for them. I put Kumho 185-70x13 795's ($45 each) on the original steel rims and they are great.

Approach like any used car, good ones are around $1000. Simple to work on and parts not too expensive.