When you say it is "wearing out", what does that mean? Has it developed "pin hole" perforations (that are caused by galvanic interaction with underlying nails or screws)? Or, is the finish on the roof just deteriorating? There's not much else that can go wrong with an aluminum roof.
If the finish is bad, it can be recoated - I'd recommend an elastomeric paint. Holes can be patched with something like EternaBond tape.
Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH
2014 F150 Platinum 4x4 3.5L EcoBoost SCrew