What you do not consider is that they were designed to accomadate the lack of support with reinforcments or they were designed to be a convertible from the start.

Many of the old convertible conversions were a mess compared to the proper ones of today.

Also if you were to cut the roof off of a HHR and hit something head on it would fold up like a slice of bread. If you look at the pictures of crashed HHR's the roof plays a important part to give strength to the car.

The HHR is made as a unit and needs all sides to provide the strength. Many modifications would be needed to make it right.

Anyone can chop a roof off but chassies stiffness will be an issue.

My Fiero has the T top package and even reinforced it is no where as stiff as it once was. Cars And Concepts did a good job in reinforcing it but still it lacks stiffness of a solid roof.

Not only is safety a concern but handling goes away with a flexing chassie. You could bounce all over the road if it flexes enough.

 

I have considered that, and you are exactly right about the need for the roof adding strength. I was going to state much of what you have, but i didn't feel like typing all of it, just making a simple statement instead. As far as modern convertibles on unibody chassis, some were designed from the ground up to be convertibles. but many were not. And yes, they are structurally compromised. Not as stiff, but still meeting the minimum safety standards. Like the HHR, most every unibody car today is designed with the roof as an integral part of the vehicle's safety features. So any attempt to make a convertible results in a compromise of some sort or another.

 

What about the guy who converted his HHR into a pickup? I know I saw a pic or vid on Youtube I believe.

 

The 2011/12 camaro will offer a convertible. I am quite sure that is a uni-body. Doesn't the PT Cruiser have a convertible? What about the mini? Geeze even the smart car has a convertible.

 

Like Doc stated cars like the new Camaro are designed to be a Convertible from the start and have the extra bracing needed.

The PT is offered as one and has to have the basket handle over the center to add stiffness. Even then it is a very floppy chassie.

The Smart is more a space frame with a removable top vs a true convertible. The regular Smart only has a thin plastic panel over the space from to start with. But again this was part of the design to start with.

You can make a unibody into a convertible it just has to be done right or you end up with a mess of a car. Often if it is not designed from the start it is a poor convertible or a very expensive convertion to do it right.

There is more to making a good convertible than just cutting the top off.

The HHR's body is like a roll cage. If you remove one part it make the rest unstable unless you find a way to give it back strength. It may drive down the road with the top off but it would foldup on you in a crash and it would have a lot of chassie shake and cowl shake. The HHR was never intended to be a convertible so it just has little in the way to make it an easy or proper conversion. With enough money and time you could build one but it would not be cheap unless you could do it yourself.

 

The trucks would be easier to do since you can use the cab shell to give the chassie some support. Also boxing in the bed will make it more rigid.

 

Just build a full body cage then, color match it and and use a tracked guide and a soft top or even a patial cage for the T's. You have to drop big bucks already

 

Why not design a convertible with a truck in mind? Makes me think of an old bronco. The way I would design an HHR convertible, would be a sunroof in the front with a romovable cap to make an open rear cabin. It would pretty much like a SSR with a back seat in the bed. Yes i agree with everyone, that probably isnt that feasible, but its fun to dream eh.

 

Speaking of a SSR. Even full frames not intended to be a concertible can be horrid.

I autocrosses a SSR and even built on a Trailblazer full frame it felt like each corner was working differnently than my seat.

It is fun to dream but unfortunatly some on the web start turining dreams into reality. It is fun to dream to fly like superman as long as you don't try to turn it into reality.