OK so as I was driving down the BLVD on my way home from work, I turned to my right and noticed a Mazda CX-7 next to me, and it had a close resemblance to the pictures I’ve seen so far to the Model Y as far as dimensions go. I am NOT comparing these two vehicles in any way except for dimensions. I’ve been keeping an eye out for any cars that seem like they are close to what I’ve seen online for the Model Y, and the Mazda is the most similar I have seen yet when it comes to somewhat the same length, height and cargo area, let’s compare specs (and guesstimates).

The Mazda CX-7 is 184.3″ in length, which almost exactly the same as the Tesla Model 3 which is 184.8″. From what I’ve seen in images, the Model Y appears to be almost the same length as the Model 3, so the length seems right on the money.

The Mazda CX-7 is 64.8″ in height, which is a little higher than my guess of 62.6″ for the Model Y here:
http://therandomthoughtproject.com/2019/05/tesla-model-y-height/

The next interesting comparison is the cargo space. The Mazda CX-7 has
29.9 ft³ of cargo behind the rear seats and 58.6 ft³ with the seats folded down.

Now Tesla doesn’t give us the rear seat cargo measurements or the frunk measurements, but their site always includes the frunk cargo capacity in the listed total cargo capacity. Since Elon has stated that the Model Y will be 10% larger than the Model 3, my guess is the frunk will be around 3 cubic feet compared to the Model 3’s 2.7 cubic feet. Tesla lists the Model Y total cargo capacity at 65 cubic feet. If we subtract the 3 cubic feet used for the frunk, this brings the total capacity with seats folded down to 62 cubic feet, which would be slightly more than the CX-7. Of course this is all based on guesstimating and no known facts about the Model Y, but based on the CS-7’s dimensions, I think it’s pretty close.

Here is an image I put together showing the 2 vehicles side by side.