I am pretty tall at 6'6" but have short legs, 32" inseam, so I have lots of headroom problems with cars. One of my dreams for a while now has been to get a car with a sunroof, replace the sunroof with a delete panel, and shape the panel so it gives more headroom. Every time I get a haircut, I spend a few weeks picking hair out of the headliner. It is rare to drive a car with stock seats and enough headrom to avoid a neck turtle situation when wearing a helmet.
My side gig is playing brass music so I have a number of friends who do brass repair for a living. They are comfortable with an English wheel and at least one also does body work on cars to make ends meet. Alternately, there are a few websites online that claim to sell fiberglass reproductions for Ford GT kit cars.
What else do I need to think about before doing this? Safety? Water leaks? How cool I will be when it is painted?
Why not replace the panel with plastic after carefully heating it and forming the necessary "bubble" then cut it to size and install?
Use a helmet or a metal bowl or similar with a sheet of plastic, some small sand bags and an oven.
This is a cool idea. I think as long as you leave the sunroof trays in place you shouldn't have water issues (more than regular sunroof water issues anyway).
Maybe try lowering the seat some how? I think a bubble would look really odd in this fashion. What about modifying the headliner? There usaly an inch or so to play with before the roof skin.
How many cars are the sunroofs large enough that they fall completely over the driver? I feel like my e30 has a pretty large sunroof relative to it's roof side and it doesn't sit all the way over my head. The jag and s4 are a definite no-go.
It has been my experience that in cars with a sunroof, as the driver (or passenger) you are not really seated under the open roof. At best, you are seated directly under the rail for closing the roof.
This is hard to find a picture for but this one may work. If this driver still hit a large bump, he's not going to have his head go out the hole but rather about 50% of his head will still hit headliner. When I wear a helmet in an open sunroof car, my head still hits the roof.
So, are you prepared to make the opening wider than the original factory opening? How much structure does this compromise? Not sure what kind of car.
Another unknown car but this guy is a long way from getting his helmet out the roof opening.
Edit: I was writing while above he was writing the same thing.
I am looking at an E36 BMW. I fit in the non-sunroof cars after replacing the seat. The higher trim levels are almost impossible to find without sunroofs.
On the sunroof cars, I will have to remove the cassette and sunroof motor whether or not I put a bubble on the roof. My thought was if I was putting a delete panel in anyway, could I get enough extra head room to scratch the top of my head while driving?
iansane said:
How many cars are the sunroofs large enough that they fall completely over the driver? I feel like my e30 has a pretty large sunroof relative to it's roof side and it doesn't sit all the way over my head. The jag and s4 are a definite no-go.
I haven't been in one. My head always hits the sunroof frame or the doorsill first.
In reply to Pete. (l33t FS) :
Your head hits the door sill?
In reply to iansane :
Whatever it is that you call the bit of interior trim that surrounds the top of the door opening.
A lot of cars have a LOT of tumblehome. Corollary: A lot of cars I will never drive if they have a rollcage.
I think what others have said regarding the placement of where the sunroof is may be the issue, but I would love to see a brass gurney bubble insert anyway 
John Welsh said:
It has been my experience that in cars with a sunroof, as the driver (or passenger) you are not really seated under the open roof. At best, you are seated directly under the rail for closing the roof.
Yeah, this is the problem.
An alternate solution would be to remove the entire roof panel (sunroof and all) and replace it with a new panel with more clearance, similar to how an aftermarket carbon fiber roof works on a race car. This is likely to involve some compromises for a nice street car, though. (interior aesthetics, noise, insulation, etc).
In reply to Pete. (l33t FS) :
Cool use of a nautical term (that I'm familiar with) but have never seen used in automotive terms. But, I did find this cool graphic for those that might not know.
In reply to John Welsh :
I didn't know it was a nautical term, I have only seen it used for cars.
Then again, that's also the terminology I pay attention to.
Nice thing about Certain 80s European Cars is they are rather slab sided in the greenhouse area. Unfortunately, I staked my motorsports flag on Mazdas. This is a lot of why the caged car I am building is NOT a Mazda.
In reply to Pete. (l33t FS) :
Here's a sample of extreme Tumblehome in fiberglass sailboats. Wood boats like even the ole Mayflower had some Tumblehome too.
One could probably do some hydroforming to get a bubble made from steel.
Thick backing plate, tap a pressure washer fitting into center. Then a thinner sheet. Then a flange cut in your desired shape (teardrop?, I'd advise avoiding sharp edges). Have a relief radius on the bottom side of the flange (could grind that in), lots of drilling holes around the flange and bolting. Attach pressure washer and fill to desired stretch.
I suggest annealing the steel to help. You could also do it in aluminum and rivet it on...
I bought the car. Here is the situation:
The sunroof is a little too far forward but it is working right now. I enjoy being able to see traffic lights. I hope my hair on the outside of the car is as entertaining as I imagine it. I still might move forward with the gurney bubble idea. It would be a metal blanking plate for the sunroof followed by cutting the oval for the bubble.
