2012 Volvo S60 Referral M37TH5
Vibrating seats were a helpful way of keeping people awake and alert ten years ago, but most manufacturers have moved on to a new method of informing the driver of a hazard. It's usually a vibrating steering wheel or a warning light on the instrument cluster.
"Various effects generated by noise, a physical vibration, and thermodynamic operations of the internal combustion engine are sometimes considered important to drivers in the field of high-performance vehicles," states the patent.
I've never driven or even ridden in an EV, so I can't write from experience. But sometimes when I'm driving, I look forward to the lack of vibration.