Rob,
Generally speaking, yes. Lexan is simply a well-known trade name, but is still polycarbonate. Kind of like calling a tissue a Kleenex, or a cotton swab a Q-Tip. However, there ARE different grades of polycarbonate. The basic is called a utility grade, then you move up into scratch-resistant, UV-coated, etc. Polycarbonate, despite being as strong as it is, is VERY VERY prone to scratching. It is a soft substrate for sure. As a side-note, one of my products that we manufacture is a windshield for Kawasaki Mule utility vehicles. We sell thousands of these units each year, and you can only imagine the kind of abuse that a windshield on a off-road utility vehicle goes through...trees, mud, road rash while trailering the vehicle to the ranch, etc. We use a utility grade polycarbonate material, with a UV coating. We place special instructions into each unit basically telling the end-user that polycarbonate, while strong as heck, is rather soft. With any polycarbonate, cleaning it must be done with a mild detergent, a microfiber cloth, or a chamois. But one more thing: polycarbonate is highly prone to static electricity. In my world (UTV windshields) the dust and dirt can quickly gather on the windshields due to this static cling. We highly recommend a product called Plexus. A lot of aircraft folks may already know about it, but if not, it is fantastic for polycarbonate (and acrylic, for that matter). The Plexus is a foam spray, and while it does a superb job of cleaning, most importantly it removes the static cling from the polycarbonate. I have no ownership in Plexus, but it works great! It's available online, but more conveniently at most any motorcycle shop. I use it on my Cessna 140 windows and it's great.
Sorry for the long reply.