Acryl wont work because its brakes at impacts. Material needs to be polycarbonate or was it polyester PETG, PET that works also. Here is what I can manufacture if you don`t want to start making your own:
Less drag = Less fuel | Aluminium wheel hubcaps | Eco Tuning --> Tuneko Ltd
Kit would include 4 round PC discs (tinted or clear) and 20 pcs of ziptie plugs and zipties. I can also heat them to little bit convex if you need them like that, so it can be done. Those ERA wheels are 10mm "convex".
Price varies little bit on wheelcover size but it will be between 150-200€ shipped to states. ( just Shipping will cost about 50$)