I put my puma in a 3 car with my tahoe . The boat basically takes up a 17 wide by 18 6 deep area. If you put it on 45 degree. The Merc on the transom saver and room to walk around the front and both sides.with the tongue swung. The motor and both back corner will almost hit the wall at the same time in a 90 degree corner.
I dont have labs but i do have pointers and shorthairs. The only thing that worked for me is to run there butts off every other day. Go somewhere private let the dog out of the truck and drive. When you think there done go a little more. good luck
I have a 2007 puma 250 proxs with 250 hours posted on this forum. If interested I will put any lowrance hds unit you would like on it. I am in Missouri and will drive any reasonable distance.
You should be able to pull the seat pan and reach the back of the shift handle. I had a similar problem but with a puma. The seat pan is heavy but easy to remove.