If you are tired of waiting to be eligible for your Lyft Amp sign, then don't hesitate to go on Amazon to get one. There are a variety of great USB/cigarette lighter powered light-up signs for under $30. I drive for both platforms and found this great combo-sign:
https://www.amazon.com/gp/product/B078R2T822/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1