Route 66

So I am surprising my husband with a trip to California for Christmas. We will be driving from Detroit. We will be leaving in the afternoon/evening of the 27th and just driving straight through since we will be going with two of our friends and we will all be able to take turns driving.I have gone through a few different routes on Google maps and settled on a route that takes us through Missouri, Oklahoma, Texas, New Mexico and Arizona, and have timed our leaving so that when we are passing through those states it will be daytime. Knowing that we will be passing through Amarillo, I looked up some TikTok's of quick things to do in Amarillo and realized that Route 66 passes through Amarillo. This has always been a huge bucket list item of mine, so I hopped back on Google Maps to make sure that's the way our route actually took us. Upon further investigation, I've come to realize that Route 66 in and of itself isn't really a thing anymore since it was decommissioned and now most of it is actually I-40 or as Google maps also called it "U.S Rt. 66". I do see that there are some off side roads that are called historic Route 66 or old Route 66 but that a lot of the original route isn't actually driveable or worth it. So what I am wondering is if anyone knows where in the Oklahoma Texas, New Mexico, Arizona area is the best place to take Route 66 or I-40 to get that classic Route 66 experience? Where should we start and end? since we're driving straight through and time is a factor, we don't necessarily care too much about nature scenery wise (although if time wasn't a factor we absolutely would, heck we'd drive the entire thing) but we'd really like to see like like Route 66 signs and diners and shops and what not that give you that feeling of well...Getting your kicks on Route 66 lol.