Looks good Lewis.
Thoughts:
I do think that WS2 might be a bit too bright in contrast with the mods (I think WS1 or 3K might fit a bit better) and might make the green legending look darker than they might be. British racing green is quite a drab colour and with contrast with the alphas I think will make it feel like they don't fit together. I could be very wrong though.
I feel in context, WS2 should look really nice against the green legends/mods. From the work I've done with colour swatches against various shades of white, I feel like the bright white of WS2 should work pretty nicely. Having said that, when I posed the question of WS1 vs WS2 in Discord, people did seem divided. If you're reading this and have an opinion on shade of white, please let me know either in the IC form, or in a message. Soon I should be able to get some photos of my RAL swatches against GMK colour ring caps which should help with this process of making this set as great as it can possibly be.
Automotive based novelties might go down well as a lot of people are at least interested in cars and a few iconic cars have used this colour. (carrying on from what depletedvespene said, perhaps a Pole winkey? as in Pole Position?)
Oh, and Icon+Text pretty please.
I'm currently working on a novelties kit for this set, and you can expect an update when it's ready. From the initial feedback I've seen people are on a similar wavelength of what they think will look good. If there are any novelties you'd like to see within the theme let me know! As for mods, text + icon is actually my favourite usually, however for this set I feel the minimalism of icon mods gives the set a really crisp feel in a way that I feel text + icon wouldn't.