I know this reply is a bit late, but maybe it will help someone in the future. I've done paint and body for the better part of 13 years and part of that was working for Freightliner's main truck plant in Cleveland, NC. As far as the toughest topcoat you can apply, it is hands down, powder coat. That stuff is very durable and hard to chip and if you have the right equipment, it's the easiest to get right. Now, if you don't have access to the equipment, the next best thing is Dupont's Imron Elite 6000 series. The 5000 series is single stage which can also be cleared, but it's made with the UV protection in the paint so no real need for clear. The 6000 series is a polyurethane basecoat/clearcoat system and they use it on Freightliner trucks as well as quite a few actual tractors because of the durability. On the paint line, we had long bolts we'd use in the holes where the mirrors mounted in the doors. This kept the doors from swinging open too wide and touching wet paint on wet paint during the paint process. That paint would build up over time and there was a guy that would knock the paint off from them so they could be reused. Otherwise, coat after coat would make a 3/8" bolt over an inch thick and it would start getting into the wet paint and mess up the paint job. The way that guy had to get the paint off was to literally beat it off with a mini sledge. It's by far the hardest paint I have ever used. Some pointers to working with it...it orange peels bad because it's so thick, so you definitely have to wet-sand and buff it BEFORE it's fully cured and by fully cured, I mean several days dry time. You want to start after 24 hours cure time but be completely finished by day 4 at most or it becomes very hard to cut. The second thing I want to point out is that it contains isocyanates. These are the absolute worst chemicals you can ever think about inhaling. If you don't wear the correct breathing protection, it WILL cause you get become violently sick to your stomach and over time, exposure to it will change you genetically, cause bad damage to your liver, and above all, it will drastically shorten your life span. This is why most auto body shops don't use it. Now, with that being said, as long as you are careful with it, don't get it on your skin, and don't breathe it, you'll never find sprayable material that will hold up better to rock chips. Think of how many 18 wheelers you see with half a million miles that still have really nice paint. This is why.

 

don't know if it helps, but warming up the cans helps the paint lay more evenly, i've noticed.

 

I've done a few bikes and a couple of cars and boats using products sourced from this company. They have a real person help line and normally ship quickly.

I recently had them mix me up some PPG two part urethane with a clear coat finish....a Honda color...tempest gray metallic...from a 1988 Hawk NT 650

It takes some careful work to get good results with a two part urethane finish but the results are spectacular and very durable indeed. I made a mistake and went out on my bike before the clearcoat was fully cured, I dragged my pants zipper across my rear cowl and put in some scratches....No worries....I waited about a week to make sure the paint was fully cured and buffed the scratches right out...When fully cured it is hard to scratch this stuff...

Expensive, however...I think I spent about $100 on the paint for one sportbike...
Hope that helps someone.


Single Stage Urethane Product Line

 

Does any one were I can get a paint code cross referance for 2002 Honda red (r-258)

 

Not sure what you mean, but here is some info on it. Not cheap though...
Honda R258 Winning Red - ColorRite

 

The hardest clearcoat that I have run across is an off brand by a company called Rubberseal. It is fully cured in 24 hours. That being said, don't wait until the clear is fully cured to sand it. At 24 hours the clear is so hard that you will spend hours sanding it before it is smooth enough to buff it. And with commercial clear coats, make sure that it isn't to humid when you apply them or they will get a kind of milky haze in the finish. You can put in other chemicals with the clear that can assist with that if you live in a really humid area.