Chopping the roof off... disaster?

[mx5tom]

Just been reminded of this by a picture in another thread, and it got me wondering.

I remember a few months ago seeing a nice looking E46 M3 (Coupe) in a garage I pass, having the roof cut off. The rest of the car looked absolutely fine, so I assume it was some attempt at a convertible conversion?

How would just chopping the roof off affect the car? I would have assumed the soft-top version of the M3 would have had the chassis considerably strengthened. Whilst this may well have been done to this car, surely it would have been cheaper to sell and buy a standard convertible M3.

No other reason for posting this, other than it played on my mind for a while and I've just been reminded of it. :P

Why would the roof be cut off what was, visibly anyway, a good car?

[TheStoat]

My guess would be it was a cheap as chips project car i.e. fine except for a major engine problem. Do you think the person might have been using it as an engineering exercise, practising for conversions of other vehicles? If it was in fine mechanical fettle as well then I'm also unsure what they were up to

Generally speaking cars do use the body shell as a way of increasing the rigidity of the vehicle thereby reducing unwanted twisting and flexing. How much rigidity you lose on a particular car after you finish with the angle grinder varies widely from one car to the next...

The only other thing I can think of is that someone's wife asked them to "convert" her husband's car after finding out he'd been to a lapdancing club ;-)

[Goodwin]

If the convertible M and the hardtop use the same chassis design etc then whilst removing the roof will reduce the chassis stiffness you will still end up at the convertible level of stiffness. However as the hardtop was designed first then I suspect the convertible had additional bracing designed in. At best the car will not handle to well, at worst you may not be able to open the doors, and if you do you wouldn't be able to close them again.

Can't think why in the world you would do it if you can buy a drop top from the manufacturer. Seems weird and expensive - unless it was just a shell.

[Urban Sports]

Why go to the effort of chopping the roof of an E46 M3, why not just buy a convertible?

About half of them are drop tops aren't they?

[TheEnd]

I'm sure someone got a telling off from the police for something along the line of a significantly modified car.

Something in the roadworthyness part of it isn't keen on big structural changes like that.

[Seek]

mx5tom said:

Why would the roof be cut off what was, visibly anyway, a good car?

CSL carbonfiber roof install

http://www.m3forum.net/m3forum/showthread.php?t=19...

[EDLT]

Maybe it was getting a roof chop:


They'd be the first to do it on something so modern afaik.

[mx5tom]

It did seem weird. I saw the car regularly being driven about (usually like a tw*t) and then what looked like the same car (don't see many M3's near me) in a small garage in the process of getting the roof chopped off.

I'm not sure, but I think the garage usually takes in scrap so maybe he'd written it off. I haven't actually seen the car since. Still don't see why they'd cut the roof off though, if it had been written off.