get sanding , dont buy rods cut up another dash into whatever size you want, or go see who ever plastic welds locally, i saw on another forum a bloke went and bought a cheap clip board(like they give you on school excursions, when your meant to take notes) that was abs plastic, and chopped it up

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i think it might have been a motorbike forum, some bloke was fixing his plastics after a crash, i think i googled plastic welding with soldering iron?? you could try whats made of abs plastic around the house etc etc you get the idea anyway