Unfortunately, the only way to get them OEM is to purchase the entire cupholder assembly for ~$120 from the dealer or online. Keep an eye out on the forum for part outs or post up a wanted to buy ad. When they show up here, they typically go for less than $50 shipped. You might even have luck finding someone with extra buttons laying around. I used to have some but gave them away.
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2011 370Z 6MT Sport Gun Metallic | ARC | CJM | Ecutek | FI | Fujimura | R2C | SPL | Stillen | TWM | Z1 | ZSpeed | |