anyone make a luggage rack that replaces the rear seat?

I don't plan on ever riding with a passenger, and I would like to be able to carry things like my gym bag on my bike, (or maybe a small cooler for a quick trip to the grocery store, etc) so I've been thinking about fabbing up some type of rack for it. My bike is a maxim x, which has a 2 piece seat, so the rear can be removed, and the little aluminum loop behind it can be too.

Any of you guys ever build anything like this, or replace a factory 2 person seat with a solo seat and add a rack behind it?
I don't really like the looks of a lot of the racks on the market, they stick out so far to the rear of the bike, another reason why I'm open to the idea of doing this.

 

there a re racks out there that bolt on behind the seat big enough to put a milk crate on. also we have a new member who put a solo harly seat on her bike looks nice
https://www.xjbikes.com/forums/thre...-still-a-work-in-progress.125284/#post-630398