I'm struggling to think of a reason why not... If it was me I'd go for it, but you might want further confirmation from someone with intimate knowledge of both...
Whilst I doubt the position of the main drive train components would have been altered, your information does suggest perhaps the linkage above the gearbox may be different. The few reprints I have (and a poor memory) suggest the Mk IV had a straight gear lever, the Mk V cranked. Why the change? Simple ergonomics or do they start from a different position?
Yes the gearshift in my V is cranked, the question is will this make a difference to the carpet, I suppose my option is to try and get one made to measure from some where.
It's a shame no owners can step forward and offer a couple of basic measurements to determine if there is a difference. Assuming that would be the only anomaly, and things like throttle pedals, dip switches, seat runners et al are the same, can the Mk IV carpet not be adapted at all? As some of it would be under the small centre console, how much else would be in view? Obviously the right tool is always best for the right job, just throwing a few random thoughts in on a blustery day
If the gearbox tunnel is higher it would mean cutting the 1V carpet under the gear leaver and fitting a piece in I should think. As you say you would think one of the supplies of these carpets should know but they don't seem to, series 1-1V that's it.
The tunnel on my V is 8" high from carpet to top under the gear stick, could anyone with a 1V check the height on their car and let me know please Thanks
It would take an hour or two (as I found on occasions I used it) to check in the parts list that I sent to you. Looking at part numbers of bodywork panels etc. you could get a reasonable idea of dimensions? It's a bit of a palaver but going through the bodywork pages of series 5 and 4, see if the apropriate parts are the same part number. Perhaps there's a part number for a complete shell or floor panel for each. Good luck!