Flame suit on, but bear in mind my HP4 also came with the rear seat cowl piece so I can swap this out as one assembly mounted on the passenger seat with just the key.
Since my old RKA magnetic tank bag won't work I decided to search around for a small tail bag. This is considerably smaller and doesn't expand but it will carry the small things I bring or buy from time to time. Thought I would post some pics up for the forum in case someone else needs a bit more storage than the tail provides. I really didn't want the strap style tank bag.
Oddly enough this is the first mod to the HP4. Who'd a thunk? But there are other things coming. Posting in general since it doesn't appear to belong on any other subforums.
I should note that the straps used to hold the "base pad" on are too short for the passenger seat as they come. I used some zip ties and doubled over the straps so they stay in place. If it starts getting loose then it will require more velcro along the strap (along with cutting a good 6 inches off the end) to get them to work as designed. I'd show a pic but it wouldn't quite show the issue. I got it off Ebay for $90. RKA isn't the cheapest but I've owned several brands over the years and they really do make great stuff.
A quick update. The four straps under the passenger seat are long enough to secure the tail bag when folded out. You don't need the base pad - it stays in place easily doing it this way. Also, you don't have to remove the rear two attach points on the bag to get to the key hole.