You can drive it but you have a leaking airbag, replace both airbags in the rear.
You have sports package that I can tell by your wheels and window trim, buy the model for Sports suspension:
www.arnottindustries.com for replacements, 200 bucks, and make sure you buy both sides, your car is 13 years old I'm sure both are due.
Do them both fairly quickly, the compressor will pump up the bags once you start driving but it is going to get overworked trying to keep them inflated. If you wait too long the compressor will be "burnt out" and you will be replacing that too.