What's a good paint to use on your bumper to fend off tiny pebbles, salt particles...
 

and other tiny rubbish you hit while driving that leaves your front bumper looking like 13 yr. old teens face. Any recommendations?

truck bed liner?

A couple things to try
 

A flex agent will add some give to the paint. it is intended as an adhesion aid where the substrate is obviously flexible. The only trouble is that it can sometimes discolors the top coat.

Another way is a good sandable epoxy primer. It'll help the top coat adhere better and not tend to chip as much.

Do not go with a lot of extra coats of paint. It will change the color and the thicker film will become brittle. Also do not go with a clear coat. It will look a lot different than the rest of the car.

Truth is; not much. There's ways to make paint harder/more durable/flexible but "sand-blasting"...
 

will win out over them every time especially on frontal/leading edge surfaces. The harder something is the more aggressive sand is at chipping/eroding away at it. At 55MPH there's not much short of rubberized coatings that can offer much in the way of relief. Sand blasting, even when scattered/unfocused is just too damn effective on hard surfaces!

Hard coatings like 2-part polyurethanes are certainly no answer as while they are indeed "hard" that seems to only exacerbate the issue. Flex-coatings don't seem to help as I had my RS2 bumper and carbon fiber hood sprayed with them and I suffer the same problem.

When sand-blasters mask they use a heavy, rubberized, resiliant tape that seems to deflect the abrasive away. Kinda like the opposite of a rubber ball off a brick wall, ie; a ball bearing off a rubber wall.

But I believe it's inevitable... if you're gonna drive head-long into granular, sharp-faceted silica at-speed you're gonna get blasted (that's why it's SUCH a good blasting/cutting media!). And you don't have to look beyond your windsheild, headlight/driving/fog/parking light lenses, rearview mirror leading edges, roofline leading edge etc to see the evidence of it.

...
 

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Dealers have been installing clear bras on cars here for years...it helps protect the front ends, but is usually installed with the paint is unblemished. It's typically installed on the bumper, leading edge of the hood (about 8-12" back), mirrors, fender flares, etc.

i'm a fan of clear bras

3rd, 3M makes a protective film... more info here.
 

<ul><li><a href="http://solutions.3m.com/wps/portal/3M/en_US/Scotchgard-PPF/Home/For_the/Consumer/Product_Info/">http://solutions.3m.com/wps/portal/3M/en_US/Scotchgard-PPF/Home/For_the/Consumer/Product_Info/</a</li></ul>

i've had several brands, ... 3M is the only clearbra i would spend money on

I HATE em as I've had to remove them from several cars. What a PITA that is...
 

they yellow (or the adhesive under them does). They tend to let go on all leading edges, especially if ya get to close with a pressure sprayer. They crack and the paint fades less under than than around them meaning when you get the clear stuff off the car now looks like a patch-work quilt of dark &amp; light colors. And it does not come out even with rubbing compound or color sanding.

My youngest son works for a detail shop and went thru the 3M clear bra application school that 3M requires before they will sell to a shop. And even he thinks it's a bad idea but he gets paid a perentage of every car he does so he encourages people based on the protection but doesn't tellem the down-the-road disadvantages. BTW he has absolutely zero clear bra on his 1 year old Accord ;-)

What a nice ethical business....or those who run it?!