Bootliners are absolutely fantastic (I am not an affiliate or anything) bought one for my Volvo and just had one for my GLA as they do such a great job.
Thick and durable, they have high walls if you have any wet gear to go in (I have an inflatable kayak, scuba and snorkeling kit I take with me in trips) my 2016 boot carpet is still like new despite having a muddy emtb in the boot sometimes too. It has been a godsend. My Merc doesn't arrive until Thursday, but bought the new liner in advance so as to be ready. I would highly recommend and they are much much cheaper than trade, tailored to an exact fit.