When the airbags are deflated, they are just along for the ride so I don't think that they would suffer any damage during off road use.

However, the ones on my RV have a minimum psi rating & I don't know why. I would suggest that you call the company (they have a support line listed in the 'contact us' tab). Ask them at least these 3 questions:

1. Do the airbags have a minimum psi recommendation & why?

2. The VX has an incredible amount of rear suspension travel. Will this cause any damage to the airbags as long as the rear coil springs remain in their perches?

3. Why do they list one compatable with the '99 VX and not for '00 or '01? Is there a difference in the suspension (AFAIK there is not)?

BTW, the airbags have very little volume and lower max pressure than tires. Any little compressor will air them up just fine.