I notice a '90 BMW 325ix 4 wheel drive (120,000km) is up for sale. I wonder has anyone out there had experience /knowledge of BMW 4 wheel drive ? How good is it ? How does it compare against Audi quattro ? BTW, is there a good "non-destructive" way of testing the quattro system ? How do I know it is working ? Or, how well is it working ? Solomon Ngan '90 90Q20V / '84 5000S