The 6 generations of the Volkswagen Passat are the Mark 1 (1973 - 1981), the Mark 2 (1982 - 1987), the Mark 3 (1988 - 1994), the Mark 4 (1995 - 1997), the Mark 5 (1996 - 2005) and the Mark 6 (2005 - now).
The Passat came along at just the right time to save the Volkswagen brand. It was the first car of the modern era for the VW brand, with the old Beetle aging and the other cars in the lineup using old technology and continuing to come with only the rear engine option. The Passat would feature all new technology and did not borrow from other VW cars.
The small first generation Passat only came with I4 engine options. The largest model was a 5 door station wagon, which was basically a larger version of the 5 door hatchback.
The second generation Passat is still the model sold in Chile, which should tell you where their auto industry is at this time. The I5 engine, with or without the Syncro, was sold with the Passat for the first time. Four wheel drive was an option on the Passat for the second generation models.
The third generation Passat was the first to use the new larger platform. A turbodiesel and a supercharged I4 engine were options on the Passat, as was the six cylinder VR6, which came standard on the top performance trim model.
It wasn't until the fifth generation Passat, sold from 1996 through 2005, that an 8 cylinder engine was sold with this car. The W8 might not even be the top performing engine sold with the Passat. The fifth generation also saw the introduction of the V6 turbodiesel. To help the Passat even further, it has one of the lowest drag coefficients of any sedan ever made.
There are plenty of Passats out there on the used car market. I suggest looking for one of the turbodiesel models. Diesel engines have fewer moving parts and thus tend to last longer, plus they get better fuel economy. I also recommend looking for a used Volkswagen Passat on eBay, where you'll have lots of options and an easy way to compare prices.