Rightline GearSport Jr Waterproof Rooftop Cargo Carrier for Top of Vehicle, Attaches With or Without Roof Rack, 10 Cubic Feet, Black

This car top carrier was great! You do not need rails on top of the car to use this, but you do need extra straps and the non-skid roof pad.I drove from Cincinnati, Ohio to Seattle, Washington with this on the roof of my mid-size car, and it did great. It got a lot of abuse along the way. I drove freeway the whole way, so high speeds, there were very intense winds, downpours in the rain and snow on the drive. It came off the top of the car every night to go inside the hotel, which was a bit of a pain but with it to prevent the potential of theft. The bag got a little dirty with all of the weather and bugs hitting it on the drive, but it doesn't have a rip to show for it. A little hosing off took care of the dirt and it looks nearly new.When you get it, put the skid-proof pad on the top of your car. This is necessary. It protects your car and prevents the bag from sliding around. Trim the excess padding. It will drive you crazy within minutes of hitting the freeway if you don't. The pad flaps around in the wind and makes a very loud noise. Just trimming the extra off takes care of that.The straps were not long enough for my car. I stopped at a store and bought extra straps to tighten the bag down. You absolutely need longer straps unless you have a very small car. My car is mid-sized, average. Maybe if you have a Smart Car or Prius or Fiesta you can get away without strap extensions, but otherwise just go ahead and get some.This bag fits a lot. I was worried at first, I didn't think it would fit as much as I needed it to. Once it was loaded up, it fit a ton. It fits more than the roof of my car could take, so I had to rearrange things and put lighter things in the carrier, but it was great.There are only a few rooftop carriers out there for cars without roof racks. Luckily this one is excellent quality, holds a ton, and stands up to weather.

We purchased this bag on an emergency whim due to us moving from California to Maryland and needing the extra storage space for our Honda Accord - so therefore, we have no roof bars.Despite the instructions we did purchase a mat for the roof, but we took the advice of a previous reviewer and purchased a yoga mat for $10 which worked perfectly folded in half - just to give the roof a little more protection. We also purchased some ratchet straps, again, just to be on the safe side due to the distance we were driving, these only cost us about $25 from a Napa Car Parts store.With the journey we took we got quite accustomed to taking the bag on and off the car every day as we stored the bags for our clothing and for our dog who rode on the back seat - overall it was quite quick to rig up and we used the straps through the car door as the supplied hooks did not fit an Accord. This worked perfectly except for when we were driving through torrential rain; the straps I purchased then acted like a wick and the dog did get dripped on a little! (But only a little!) If waterproof straps are available anywhere this would be a better option.Suffice to say, driving from CA to MD and going through 13 States, we literally went through EVERY type of weather; from blazing sunshine to a snow storm and also through the edges of a major storm where we hit very heavy rain and wind - the bag itself proved itself to be very much waterproof - not a drop got inside the bag and everything remained as dry as a bone! The material it is made from is certainly hard wearing, and very easy to clean (essential considering the front of the bag will end up being a bug board!)I have noticed a few people ask and comment about noise; I found that as long as the straps were tight, the noise was minimal, if they are too loose then they will vibrate and make a noise. I also noticed earlier people comment about the fuel consumption on their car being improved with this bag fitted: this is utter rubbish! There is NO WAY your fuel consumption will improve with this bag fitted and full! The aerodynamics of your car are being massively altered. You will notice (depending on your vehicle and the load within the bag), that the handling of the car will be different at higher speeds and higher wind speed, this you will no doubt easily adjust for as you get used to driving with it fitted.Overall, despite this being an emergency purchase the only thing I can fault it on is the wicking effect of the straps if you feed them through the car and end up driving through torrential rain, but like I said above, if you can get hold of some straps that are waterproof then this won't be an issue.