i've used 303 with good luck. have minimal streaking. you could try ultima ttgp. when i was test 303 and ultima the ultima seem to collect dust more than the 303. the test area was 2' x 2'. the ultima seem to hold up better and i liked the look better, but didn't like the way it seemed to collect duct. 303 looked good until the first rain then it wasn't as black, but still looked good. 303 didn't collect dust like the ultima did. all said and done i went with 303 and apply every month. ultima will last longer and looks better, however it does come with a higher price tag. i use ultima ttgp on my tires and it doesn't seem to attract dust like it does on the tonneau cover.
a side note. when i bought my tonneau cover it came with a sample bottle of 303 cleaner and 303 protectant.