Is this a good idea for a product?

Not very aerodynamic.
Doesn’t seem as if it would be easy to reach while sitting in the car.

It is either for a place to put your coffee and/or to prevent spilage if you forgot to bring your coffee in the car? Maybe a beep if you forgot?

There’s always the doctrine of personal responsibility.

Remember to take the cup down before you put the key in the ignition.

Accidents happen… their might be a need.

Most car roofs (rooves?) are level enough to just put a cup on it as is.

@ragingloli Till the car starts and moves, then your out of a $36 coffee.

@ragingloli I trust your judgement. Should I drop it? Or do I see where the rabbit hole goes? I have no money to invest in a hairbrain scheme. Its out of my comfort zone and am looking for excuses to back out.. Unless it is a legitimate good idea?

You’re eating macaroni and cheese, @RedDeerGuy1 , but you buy $36 coffee? Misplaced priorities.

@elbanditoroso Just quoting the Lego movie. I don’t drink coffee. Toungue in cheek.

Everything on cars is about low drag to increase fuel efficiency. I’m afraid the little used, water, dirt, snow gatherer would not work out.
Here is an item on the subject, somewhat, that might show you what I mean: Big Diesel trucks get 5 MPG if they are doing really well. Some used to have a chrome screen type muffler cover over the exposed exhaust system. But this screen, when eliminated, increased fuel economy by 1%. So the miniscule savings was considered a design improvement, even at 1%.
One thing Obama talked about (that I considered totally bogus,) was increasing fuel mileage by a considerable amount, and I always thought that idea was just nuts! Vehicle manufacturers have been cutting all sorts of corners to get MPG’s where they are today, how could they really improve it any more??
So you see, in my opinion about automotive aerodynamics and automotive design, your cup idea won’t fly. (No offense intended.)

@kritiper Its an easy work a round. Just put a sinking cup holder in the roof. That doesn’t interfere with the aerodynamics of the car.

It increases the production costs of the vehicle, and makes for a point in the roof where water could get in, increases thickness of roof, weight of vehicle, or it could cause wind noise, which are other unwanted issues to name a few.
Cars are so expensive now. Do you want them to be more expensive???

@kritiper No. Just giving my idea a fair chance to succeed. Should only cost $2 bucks. People put kyack racks on cars. So it doesn’t disqualify my idea.

Go for it if you really want. I don’t foresee there being much of a market for this, but then I probably would have said the same thing about the Pet Rock.

You seem intent on this idea. Logically speaking, it “might” work; however, would the general public be open to the idea???

Here is the US some states have this campaign going targeting distracted driving. Get caught talking on your phone…you get a ticket. Get caught picking up your $36 cup of coffee & taking a sip…you get a ticket. We can now be charged with DWD (Drinking While Driving) which carries the same weight as a DWI (Drinking While Intoxicated).

In my particular case, my left arm is paralyzed so I have to drive with my right hand. How do I reach the roof top holder??? I can’t reach up with my left hand & IF I reach up with the right hand, my car will be in a ditch before I can even reach the cup. IF perchance I run over anyone & they die, I’m going to be charged with reckless driving as well as vehicular homicide.

Another thought…how are you going to size the cup holder??? You said it could be recessed into the roof. Will the size be scaled to handle a 12 oz cup of coffee or a coffee mug brought from home or will it be for the 40 oz stainless steel double insulated wall with a handle???

WHY would you put your groceries on top of the cup holder in your car to begin with??? I put mine in the trunk or the back seat. My cup holder is within arms length of the driver’s seat & it would be dangerous to drive with that many groceries in a position to fall over onto the driver!!!

i know that I’m only one person, but I would NOT have a need for a rooftop cup holder. As a matter of fact, I have driven off with my cup on the top of my car & after the 2nd time, I STOPPED forgetting to put it into the inside cup holder!!!

Keep working on your design & once perfected take it to the car makers & see IF they are willing to invest in it!!! Much like Darth, I didn’t invest in (nor did I buy) the pet Rock!!!

I might also add that even with a design that is flush, water could get in there, freeze and cause a leak.
But go for it if you want. Do a patent search first, since this is a new idea and you don’t want to infringe on someone else’s idea, if there’s one out there already, and you don’t want anyone to steal your idea.