How can I improve this tire net?

I really like how strapping down cars has evolved from chassis mounts to holding the wheels/tires.  
 

for two decades I've been strapping through the wheels and pulling them forward and backwards. 
 

but I don't like the abnormal stress it puts on the car.  So I recently got a set of these nets that go over the tires and then to two mounting points. 
 

I wasn't thrilled about two ratchets per corner but figured it'd be fine.  What isn't is how the center strap isn't held in place by anything.  It can and does just fall off while trying to get in place.  It's nearly a two-person job. 
 

I have some thoughts but wondered what the hive thought about keeping that center strap in place while I positioned everything but in a way that doesn't interfere with the straps' movement as I tighten everything down. 
 

pic for clarity. The center strap is that 12" or so one that says snake strap 

You haul trailers use a version that puts the greatest tension linearly around the tire front to back. I'm not sure how useful it would be for you to get a look at one, but it shouldn't be difficult to find one. 
 

I'd like to see more, I'm interested in this topic. 

In my opinion using those straps puts way more stress on the car than just strapping through the wheels in the direction of travel.    If you're set on using the nets I'd get a set of the ones that are sewn together.

I like the radially oriented straps, as that's the direction the tires are designed to take loads.  I used a set of Mac's and we hauled a 3800lb Camaro 4000 miles without any issues.  Mac's come with rubber blocks to prevent the strap sliding on the tire.

https://www.macscustomtiedowns.com/straps/automotive/tire-block/e-track/p/512002/

My biggest dislike about the system was it required a significant amount of e-track on the ratchet side of the tire to get the ratchet out from under the bodywork where you could manipulate the ratchet through 180*.

Other than that, they worked great and never came loose.