Lots of leasing experience here both with GM trucks and my wife's cars as well. We take extremely good care of our vehicles and there's a first time for everything, BUT I haven't done a lease turn in since 2001. It seems that at the end of our lease that our vehicles always have equity over the lease buyout price and therefore we trade them in and use the equity on the next one. If you trade the lease, it won't matter what mods have been done. It's just like trading in any other vehicle. The one downside is if and when the trade in value is below the lease end purchase price you would have to turn it in or eat the negative equity. So far, knock on wood, I've never had that happen. The best example for us was during covid and the craziness of the used car market in 2021 when my wife sold her 2020 leased car 19 months into the lease for $5400 more than the payoff. She pocketed the equity and leased a new 2022 model of the same car. I highly doubt that the market of 2021 will exist in the future, but even if you have $500 equity, trade that sucker in at the end of the lease if you want a new vehicle.