My rear rests on pool foam noodles. They are collapsable, and firm, and slide in real easy. All I had to do is lift the seat cover up, and not even have to take it off to work on the seat. It has worked great for 12 months, and I am considering putting a few more in to firm it up even more.

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85 300CD Turbo "Das Polluter" 230K sold for $3,000

98 BMW 323is