A hint. FOAM is crucial and it is expensive and limited in scale of quality in Mexico. I brought fabric referred to as "Theater Cloth" with me. You have to ask a good fabric store in the USA the advantages of theater cloth. For my poor back a lamination of several grades a foam brought forth a near miracle for my herniated disc. Top quality zippers make covering removal a snap to wash fabrics which I insisted be extremely breathable. I even used Kevlar thread in the driver seat. It is not cheap but it will not break. Period.