Those were excellent cars, well built, and stylish. I know a couple of people that have those in my neighbourhood and they have almost 300k Kms and they still run like a clock with those robust V8 engines and solid transmissions although gas mileage leaves something tb desired. That said, you can't trust anybody, so have a mechanic check it out and if it's good to go, I would snatch it. Ik Lexus is more expensive and more reliable than Infiniti but they can still be excellent depending on which model you get and they tend to be underestimated IMO. 

I converted to odometer to miles it's about 170000km

I think you meant 110,000 km (68,350 miles) because I assume that you're in Canada so the mileage is in kilometers. Anyways, I would pass because they'll turn to money pits at around 90K-100K miles (144K-160K km). But lower miles like that is alright, but you're better off with a Lexus LS 430 as it'll outlast the Infiniti, although, the Lexus will still be expensive to maintain. You could get a Ford Panther car such as a Crown Victoria, Grand Marquis, or even a Lincoln Town Car as they'll still run if maintained.