DIY/Buy online kayak cover for PERMANENT roof rack storage

I keep my 12' kayak on the roof of my SUV permanently as I live upstairs in an apartment and dont have any other storage solution for it.

I'd like to get a cover for it, but all the ones I see online are either:

1. Decently priced, but a universal fit style that will not be as snug as I'd like, giving me worries of it being buffed by the wind while on the highway. As well as just looking kinda ugly in my opinion

2. Ones priced higher than I'd like to spend that are made from material that is more stretchy, achieving a more form fitted look and function.

Does anyone have any homemade solution or online buy recommendations? The kayak is the one seen here but not the 10 foot one the guy has, a 12 foot one (it was literally impossible to find a site that sells mine) : https://fishingworld.com.au/boats/kayaking/marvel-kayak/

My thoughts on DIY would be to get some fabric tarp and cut it into the desired shape > Use some sort of heavy duty contact cement to seal the seams and put a zipper on it. But im open to suggestions