Vin is on the left windscreen pillar, there is the gas tank sticker but raely there these days, which has all options on it, always ask if they have it or is it still on the tank.
* check underneath for chassis rust
* check if headlights/wiper door work properly, if not its a vacuum leak (pain to find leaks)
* check windscreen pillars for rust, take off the the covers and have a look (if they let you) another clue is if the pillar covers are lifting a bit means rust under it