For those of you who use your "sport wagon" to actually carry something. I leave this tip. I had a pick up truck and had bought whats called a bed extender. Its a contraption that slides into your Reese hitch. its kind of T shaped and allows you to carry longer boards. Recently I carried 8-8'x 10"x 1" boards and 7-10'x 10"x 1 boards. I didn't have to lay the passenger seat back but did slide it all the way forward. I had totally forgotten about the thing and have been carrying boards on my dash. I did add a trailer hitch which helped me remember but would have added it just for that if I had thought of it earlier. I never would have been able to carry this load without it.

I used the license plate bracket for a tie down as I was on the road and desperate.

Notice the 8 footers are behind the drivers seat which isn't slid forward.

This won't work to carry 4'x 8' sheets of plywood since the hatch isn't wide enough. but if you have the store cut them in half at least you can carry the length of the things without having to screw around with the front seat. Its also less stressful since on my car the seat doesn't lay back flat so it supports the load awkwardly.
Remember to allow for airflow so you don't suck in exhaust fumes through the open hatch. I could smell it so I played with the windows.
BTW the boards are for my new utility trailer. But the bed extender works nice enough to use for just a few boards so might use it instead of the trailer at times.
Another tip is to pass a small rope through the hatch latch, then close it. This shuts off the door open beep and gives you a place to tie the hatch down. I tried this on the side of the road but after triggering the latch. I couldn't get the rope through so gave up.

 

Thank you for sharing, but readers need to balance the need and the risk. Due to exhaust in the back, it is not recommended to drive with the rear-hatch open. There are other options like some big box stores offer extremely cheap truck/van rentals. Please use good judgment.

Salim
ps: It is much easier to give advice ... in this particular instance I too have carried stuff in my RX which in hindsight I should not have.

 

Reason No. 1,247 why I have owned my trusty 1999 Ram 1500 pickup for nearly 20 years. I do not drive it often (less than 500 miles per year) but when I need a truck, I need a truck....

 

I bought this a few years ago, using the excuse that I needed covered secure storage space while my old garage was torn down and the new one was being built. Since then it's come in pretty handy when I need to move stuff like lumber around. Not the least expensive option out there, but cheaper than having yet another rarely driven vehicle to insure and maintain.

 

Great idea. I have been using a bed extender to carry my kayaks for a couple of years since I sold my kayak trailer as I no longer had space to store it. The only problem is the constant beeping because the hatch is open. I wrap my kayak tie down straps through the space for the hatch struts. Not the best thing, but I only travel a few miles. I should install an eye bolt inside the hatch for the straps.
I did load it up once with a lot of lumber like the picture above and it held up just fine for the few mile journey.