I have 217k on my my 318ti and have a long list of repairs that have been done to it. I mean, you gotta take care of the baby, right?
I have encountered all of the issues previous posters mentioned:
OIL LEAKS
About 60k ago, it was the gasket leaks--all were replaced. I do not have a garage, nor a place to perform this type of work (unless it were on the street), so I paid to have all of the gasket work performed (in stages). It cost a bunch of money for the labor.
COOLANT
I recently experienced a coolant issue with mine, and it has never worked properly since. Through the fault of my mechanic, after installing a radiator he missed identifying two plastic tubes specific to the m44 engine, all the fluid leaked-out and blew a head gasket (like Jesus mentioned above). My mechanic did fix the head gaskets, the two engine specific plastic tubes, and replaced the temp gauge at no charge, but different overheating issues are presently still amiss. The fan does not activate when the car is running. It can be overridden by turning on the climate control, but that does not solve the problem—it gets hot when idling (like in traffic, driving around town without traffic, etc).
The car you are looking at does not have a properly working temp gauge? Whew, that is a nightmare waiting to happen! My 318ti is my daily driver and, as of late, it has been a nightmare. I hate to say it, but it is true. I have taken it into the shop 6 or 7 times in four months.
WINDOWS
Also you mentioned interior panel coming off. That would likely be because the owner has made numerous window repairs and had to take the panel off to do it (paneling clips and their brackets get messed up). 318Ti owners have issues with their windows messing-up. Please view our beloved “WINDOW FIX” page. Cool Jess did a great job on that one, btw!
http://www.318ti.org/forum/showthrea...ght=window+fix BMW really screwed-up with the ti's window. Which is why Cool Jess's window posting has been viewed over 59,000 times.
Best,
Patrick