I just purchased a piece of luggage that fits perfectly in the trunk compartment of the ISC with the top down. It is actually a World Tour Keyboard Gig Bag 38 X 15 X 6 from ZZounds.com. Item No. WOR KC18S10N. This bag is of good quality, has full double zippers, and is padded. The price was $30.95 with free shipping. I was really surprised at the quality for that price. Extra thick 20mm high-density padding. Water-resistant PVC-backed Cordura material. Heavy-duty 10mm metal zippers with oversize pulls. Large gusseted storage pocket, two zippered pouches on the front, and a 5-year warranty.

Sounds great - do you have a link so others can look/purchase the bag?

https://www.zzounds.com/item--WORKCSN

Only ten years later.

Anyone have a solution for carrying 2 golf bags. Maybe a trailer hitch and some sort of lockable container that would hang off the hitch?

Here are some pics of the bag from zzsounds in my 2015 is350c.