We currently have four rows in the van with rails for fifth row is under the carpet. The rear (4 person) seat is actually separate pieces. The fifth row rails looks identical to 4th row rail. By add fifth row seat which means I have to make fourth row to be three person bench like 3rd or 2 end seats. But three person bench seat legs would not fit into current fourth row rail system which is 2 rails per seat. Do anyone know if there is way to adjust three person bench leg to fit in fourth row rail??
Thanks!

 

The 5th row split seat costs about $1200 for a very clean used one on eBay. Otherwise your only option is to reposition/fabricate new rails, which is an extremely difficult job.

 

Or, remove the upholstery(for safety) and cut/weld the feet in the correct position to fit the rails.