Touchless is fine but won't get a car really clean. You have to physically interact with whatever is on the clearcoat. I used to wash my G35 at touchless washes then dry with a white terrycloth...and the terrycloth always got dirty.
Hand washing with the 2 bucket method is the best, but second best is touchless. 3rd best is mechanical washing with the silicon bristles that whip your car all over the place. The biggest danger to a mechanical wash is the brushes hanging onto dirt, grime, and grit from other vehicles and smashing it onto yours.
My dealer uses a mechanical wash and it scratches the clearcoat, so from now on I'm bucket washing only. Although, I did have a Bentley/Mclaren dealer wash it and it was 100% perfect inside and out. I bet it was touchless with lots of hands-on drying there, especially considering the cars they sell.
One last thought. Before you go on a road trip where you know grime and bugs will be a problem, you should put extra coats of synthetic wax on the forward facing surfaces as well as the vertical part of the trunk and the rear bumper. Synthetics tend to have a short life but are generally hydrophobic, which means water and wet things (bug guts) tend to roll off rather than stick. Plus when you go to powerwash the bugs off (or pretreat and carefully remove them), they will come off easier since they're not adhered to and etching the clearcoat.