A MKIV case can be used in place of a MKIII but not the other way around.
The casting was changed.
There are a couple version in each MK so you need the right one.
The internals change by model and year so you cannot drop a MKIV into MKIII and expect good results. The TCM is set to the engine requirements and gearing in the tranny.
No, the floor pans are completely different. The MK3.5 will fit the MK4.
Simple answer is yes.
No they do not. The Mk3 uses an entirely different headlamp as compared to the Mk4. They will only fit if you swap the front end of your Mk3 with a Mk3.5 Cabriolet. Furthermore, Hella Makes Headlamp units that look very similar to the mk4 headlamps.
Yes, if they are from a GTI or VR6 mk3. Ordinary mk3 wheels are 4 bolts 4x100, while gti and vr6 are 5 boolts 5x100 same as mk4.
yes they will
1998 Mk3 1999 Mk4
No they fit different, although mk2 and mk3 and some mk4 polo gearboxes will fit. You want an 8P gearbox.
yes as long as they are the same stud fitment. The mk4 golf is 5x100 bolt pattern and the mk3 golf is 4x100. unless it's a vr6 model which has the 5x100 bolt pattern so in general the mk4 wheels will not fit a mk 3.
No they can not. I made the mistake of buying some but they are completely different from MK4's so don't waste your time.
You need to modify the mk4 steering wheel to fit. Get the 3.5 cabrio wheel. It looks similar and no mods required
Make sure that MK3 is 5 stud as they have 2 different stud patterns - 4x100 and 5x100. Mk4 is 5x100 pcd (bolt pattern). So make sure you have the correct fitment.
Can't do it unless you fit a custom kit. Wouldn't recommend it though, get a MK4 with CC instead.