bjhille

I own a SC430, but my parents recently purchased a 2015 ISC 250. The sound system sounds okay from a mid and high perspective, but it's missing that low-end punch that my car has. My Dad has taken the ISC to a couple of audio places recently trying to add/upgrade a sub for the car and was told there was nothing they could do. My car is a convertible and had a stock sub. Does this car have a stock sub? Has anyone upgraded the sub in the ISC?

Thanks for your help. Brian