Part one of random things I think mechs would fetishize/find hot-
Whether it's their little organic friend wiping them down with a soapy sponge and a nice cloth, or being put through a big industrial carwash and those massive brushes overstimulating them to hell- I feel like it'd feel good. Nice cool water running over hot plating, fluffy soap cleaning away grime and grease so their paintjob is all pretty again.
This applies to robot forms and alt modes, of course.
Maybe while they're in robot form their human washes their spike clean (which is probably about the size of them) and they end up overloading and they have to be washed again and again until they can resist. Perchance a lil frotting against a brush because that absolutely must feel good.
And of course we cannot forget polish!! They gotta be all shiny and presentable!! One of those buffer things has to feel amazing against a spike or a particularly sore joint, buzzing and working out all those scratches. Like a massage gun!!
Now they're all prettied up and ready to flaunt themselves to their team!!
