> There's a saying that a new car loses 50% when you leave the lot.

New cars in no way lose half of their value when you drive them off the lot. The saying is that a new car loses ~10% of it's value when you drive it off the lot [1].

[1] https://www.carfax.com/buying/car-depreciation

Right or wrong, the _saying_ is that "a new car loses half its value as soon as you drive off the lot." I've heard that repeated from many people across multiple regions in regards to buying a new vehicle. I've always heard half, never 10%, even if 10% is the more demonstrable amount.