Baldnut
So I mentioned this stuff (crap) in another Caught Speeding!? damn.. thread and promised I would do some testing and post my results...
http://amzn.com/B000LNVC1M
Amazon.com: Reflect-All (12 oz. can): Home Improvement
Short answer, don't bother...
Long answer, I tried both, several times, with different variations on the application (based on label instructions however) and found neither of them to be effective.
My belief as to why, you're starting with (at least here in Colorado) a surface that by design has a HIGHLY reflective background and intentionally flat black letters. However effective these sprays are, they can't overcome the extreme high-contrast of the two surfaces. The spray makes the black letters slightly reflective and the reflective background even more reflective. End result is you've simply changed the reflective values of each area, but not the overall contrast, 'end result is that you can still easily read the plate...
If there is some magic application method that significantly increases the effectiveness of either of these, it's not within the realm of mere mortals using rattle cans.
Before...
After...
1st product link is on the right, 2nd is on the left, not hardly any difference for the 1st product...
So I mentioned this stuff (crap) in another Caught Speeding!? damn.. thread and promised I would do some testing and post my results...
http://amzn.com/B000LNVC1M
Amazon.com: Reflect-All (12 oz. can): Home Improvement
Short answer, don't bother...
Long answer, I tried both, several times, with different variations on the application (based on label instructions however) and found neither of them to be effective.
My belief as to why, you're starting with (at least here in Colorado) a surface that by design has a HIGHLY reflective background and intentionally flat black letters. However effective these sprays are, they can't overcome the extreme high-contrast of the two surfaces. The spray makes the black letters slightly reflective and the reflective background even more reflective. End result is you've simply changed the reflective values of each area, but not the overall contrast, 'end result is that you can still easily read the plate...
If there is some magic application method that significantly increases the effectiveness of either of these, it's not within the realm of mere mortals using rattle cans.
Before...

After...

1st product link is on the right, 2nd is on the left, not hardly any difference for the 1st product...