Like most collectors, I LOVE this Hot Rod -- a legit mini masterpiece in engineering and a better looking/proportioned than MP-28 Hot Rod IMO. The only thing I can critique this figure is that he can't have the Matrix inside his chest in bot mode and I have to set the matrix aside in alt mode.
My dead simple fix is to glue a 5mm peg (which anyone can snip from any TF gun accessory with an extra long handle) in the underside of the front engine in car mode. Then I swiped the matrix with Earthrise/Kingdom OP (because the hole of OP's matrix IS the standard 5mm, while Hot Rod's slightly bigger) and cut some plastics off of one side the matrix's "ball" flush against the silver handles so when I peg the matrix to newly glued peg at the underside of the car, I still get the clearance needed for the car to roll on 4 wheels.
Hot Rod can transform between bot<->car back and forth without needing to remove the matrix.
Next, I also drilled a 5mm hole on the back side of the lower arms. So that when Hot Rod's hands are hidden and using the pizza cutter and welder(?), he can still have his guns blasting at Decepticons.
With these mods, I can have all his accessories attached to him except the matrix effect. What to do? Hmm... I simply tucked it behind his head. So Hot Rod can look like the patron Saint of Speed and Youthful Recklessness that he is, for giggles!!!