GF's earings in the ashtray
been in the glove box lately and slammed it shut??
done any work in that area lately - last few months
usb cable from the ECU ?
have to try stick your head under and grab and shake a few things gently and go through elimination
nothing I can say oh yes that happened to me and it's .....
doesn't sound like leaf litter etc..
(ps. I'll go grab some photo's of the GT'R's steering wheel today - still in shop )
edit: just a thought - you haven't got any crusty plastic dried out from age fall off. like front dimsiter vent clips
aftermarket radio chasis or screws..