R02 vs R03, visually not too dissimilar but almost every surface has changed. The story of the development is lots of small changes to drop drag while trying to maintain load.
Floor: Moved to a more rounded diffuser among other geometry changes to try and improve the performance at the rear. Floor edge change to compliment the new sidepod undercut.
Floor fences: Minor geometry changes for a small performance gain.
Sidepods: Higher inlet lip with recessed 'top lip' to make the flow work. Allowed me to drop the supporting structure under the mirror but had to abandon the slides as I needed more volume at the rear to cool sufficiently. Reworked the shape of the undercut to help deliver better air to the mid floor and control front wheel wake.
Nose: Similar to R02 but terminates on the top side of the front wing. Just some modelling tidy up with a small performance gain.
Front & Rear suspension: Minor adjustments to tidy up some separation.
Rear wing: Flap and beam wing reshaped to drop some of the drag I'd piled on for Monaco. I think the rear wing is my weakest area on the car at the moment, the efficiency just isn't where it could/should be.