I wish I still had that one post I did a few iterations ago about creating catgirls with polymer muscle and cartilage under the skin, wiring the false upper ears with cochlear implants, and routing it down into regular ears. The same way they do amputee nerve reattachment, do the same with the temples, allowing motor neurons to connect to the muscle implants, so your catgirl can flick her ears or even reorient them a little, with practice. Like those folks who can wiggle their ears, or can't, as it were; tie it into that neuronal line.
The bonus would be getting quadraphonic sound, filtering for even better by blending human ears and the implants, though you'd have to find a way to adjust them for loud sounds. Maybe some kind of canceling; it shouldn't be hard, and you don't even have to open the skull to generate an ear canal.
Everything else is just practicing saying 'nyaa' and being cuddly, so...yeah. Catpeople indeed.
Oh right tails. Same structure - artificial plastics and cartilage to form a tail structure, add in skin grafts and/or artificial skin implanted with things...once again, tie the tail left-right muscles into the upper hip for activation, and presto. Instant swishy tail.
...i really need to monitor my medication don't i...
