It's easy to determine what regional port installed "accessories" can be included which will be added to the MSRP. I have noticed it's region based, and can only speak about Gulf States region. If I put in my zip code into the Toyota build configurator and build my GRC, I can click on the accessories tab and there will be all the possible port installed accessories for my region. Fortunately for Gulf states region, there are only 5 options. Unfortunately from what I've seen, all 5 options are "installed" at the port and included into the MSRP. All other regions seem to have more than 5 port installed accessories, but don't know if those regions install all accessories as well. It sucks, because I don't care for most of these accessories, and the accessories I do want (ie. All weather floor mats and cargo mat, door sills, etc.) are not offered in my region. Fortunately all 5 accessories for my region only tack on an additional $1k to the MSRP, so could be worse I suppose. It is what it is, and these accessories (at least for the GRC) are non negotiable.