Vacuums are the highest income generator at the car wash so you want your vacuums to work flawlessly. I’d look into buying some new vacuums. If the vacuums you have not are in good shape, not all torn up, dented and still look good I might consider retrofitting these filter bags into the vacuum. http://store.windtrax.com/storefron...&order-uom=EA&warehouse-id=1&item-number=8079 I’ve done this before about 25 years ago with some old D&S vacuums that had a filter bag like what you have.
Since it's steel, another option would be to cut the hole larger and use the Adams bushing-type bags. You'd have to fashion some sort of hold-down for the motors. It's not the best filter system there is but I'll bet it's better than what you have.
Thanks for all the suggestions. I visited with Carolina Pride at the ICA show and as luck would have it, they have about 60 filter bags on hand as "old" inventory. Should have one by the end of the week to confirm it fits then will replace all. Vacs are in great shape otherwise.