Um.... My desktop drive has been in service at least that long.... in the car, horizontal and in car wrecks that bent 2 frames.
In my Jeep I should place my HDD vertically as I'm going to do some extreme rallying, those rubber protections would also help, now I just have to look for them. I know this is offtopic but are motherboards and other internal components also prone to damage by vibration?
As it has been said over and over again:
The orieentation of the HDD is not so important as secure mounting.
The debate over horizontal vs vertical mounting will rage on until solid state drives become cheap enough for the average joe hobbyist to purchase.
ANYTHING is prone to damage from vibration. It all depends on the intensity of the vibration.
With a motherboard, lots of vibrations can cause components to come loose and render the board unusable.
It's not likely that the vibrations in a vehicle would be strong or intense enough to cause damage to a motherboard. The more likely scenario is a heatsing/fan coming loose causing an overheating issue.
I don't know if we are worrying too much, I mean data loss is a problem, and we rather not take risks, and now I'm getting worried about motherboards...
Personally, I don't think the rubber sheet will do anything helpful as far as dampening vibration.
Honestly, unless you're doing durability testing on a vehicle and driving it consistently over washboard roads, you're not going to create enough vibration for there to be a concern.
Hard braking is NOTHING, as far as force is concerned.
If you read the thread, one user totaled two cars and the hard drive still functions like clockwork. A crash that will total a car is more force than the braking from even the fastest race cars.
DON'T WORRY SO MUCH ABOUT IT!
Mount all your hardware securely and you'll be fine.