I am going to look at a 413 tonight (1992), it will be my first 4x4.
I have had a long line of air cooled vw's, all modified / resored to various extents, so i know my way around a tool box!
What i need to know is....
   ...are their particular problem areas to look for?
e.g. 
rust traps, signs of mechanical trouble etc etc
any advice?