yes, it has an airbag. No smoke from exhaust...Also, listen to the exhaust, make sure it doesn't sputter. Look at the front spoiler, underneath to make sure it isn't broken or cracked. Those Z's are low! Um....also look for even wear on tires. Check A/C and heat. Make sure the car runs fine with both. Ask if it's gone through a Nissan diagnostic. If it has, ask for the write-up. If not, tell them you want to do one. Hmmm...what else??