I've had good luck by first attaching a plastic disc to my dash (using 3M double-sided tape adhesive) and then attaching a good suction-based phone holder to it. It's critical to let the 3M adhesive cure for at least 24hr before attaching your phone mount (longer in cold temps). Placing a weight on top of the disc during the curing process will help create a strong bond.

If you're worried that removing the disc may damage your dash, I've done it several times with no issues. Just be sure to pry it up very slowly,. Using a hair dryer on high heat, to heat up the disc while prying or placing some dry ice on top of the disc, to freeze the adhesive, and then slowly prying up also works. Be sure to use a plastic pry tool so you don't damage your dash.

Disc: https://www.amazon.com/your-orders/pop/ref=ppx_yo_mob_b_pop?_encoding=UTF8&gen=canonical&lineItemId=lllhqxnnlntrsny&orderId=113-5182093-7279435&packageId=1&returnSummaryId=&returnUnitIndices=&returnUnitMappingId=&shipmentId=DHchYL200

Magnet-based Phone Mount (mine is discontinued, but something similar will work;): https://www.amazon.com/gp/aw/d/B07TXHJ1P9?psc=1&ref=ppx_pop_mob_b_asin_title

I'll try to add some pics.