I initially had a problem with this bar (7503) in the sense that Amazon accidentally sent me one that someone else had tried to mount. i.e.. - a used bar. I also had technical difficulty installing the 7504 bar in that the track system was defective. The track system is how when you tighten the screw with the special tool it tightens the rubber wrap around clamp. As you're tightening the screw a piece of metal should slide easily through the track into the AeroBlade. Mine got hung up and stripped.I ordered a 7503 and a 7504 for my 2013 Honda Odyssey. To Amazon's credit they overnighted 2 new bars to me. However they did not arrive till 3 days later. Amazon technically overnighted them on Wednesday but the tracking number came Thursday. One bar came on Friday and the other on the following Monday. Sadly I did not have them for my trip which left on that Friday. But I survived without them.When I returned I had to return the defective/used bars and open up the new bars. Having gained experience from the 1st set I easily mounted the 2nd set. I recommend that while turning the screw make sure the metal is tracking nicely by pushing it down and watching it slide into the AeroBlade and alternately moving from one side of the bar to the other to torque evenly. Do not over tighten either - just enough to see the rubber clamp stretch and get tight. There will be some space between the rubber clamp and the bottom of the bar - don't try and stretch it until the space closes - too tight!These bars are solid and more substantial than the Honda OEM roof bars. They also can be moved forward of the Honda fixed position allowing for bigger boxes (not hitting your tailgate) and more flexibility. They sit high enough off of the car so that the clamps on my Thule Roofbox don't hit the top of my car. They do come close though so either use a towel or a good tall strong friend to make sure you don't scratch the paint.I'm giving it 4 stars instead of 5 for these reasons: Since the gap between my factory raised rails widens as you go closer to the front of the car the AeroBlade, while allowing for different widths due to spring widening system, still doesn't meet up with the front portion of my car. On the other side of the connection it is flush but because the car's rails flair aggressively the front part of the gap is open, maybe a 1/4 inch. This could mitigated by another adjustable piece of rubber on the front side. Hard to explain but it isn't flush. And it could be with more engineering.Also feel that the if you remove the rails a lot that the tiny metal part that receives the tightening tool could get worn and stripped. Already the tool is worn a bit from one tightening session. I'm glad I have the "virgin" second tool from the other bar.As a side note the bars do not come with locks... All in all there are no whistles and only minimal wind noise is heard. They are solid and "cool"!