iPad Mini Size Question

I cant find a definitive answer online .... Do they iPad Mini 1/2/3 all share the same chasis? Im looking to make a car mount for my mini 3, but i'd rather buy a cheap broken mini 1 to use as a template since they are going for about 30 bucks shipped .....


Thanks

The 2 and 3 are the exact same chassis, and I believe the 1 is nearly identical to them (very slight thickness difference). To my knowledge, cases should be interchangeable between the 3. The 4's dimensions started changing quite a bit.