Fitting Frequently Asked Questions

Whilst the windows are reasonably simple to install as they are mostly direct replicas of the OEM glass in both curvature and profile, there are some tips below and answers to some frequent questions.


Are they pre-cut to fit?

YES – all our windows are trimmed to the size of the stock windows so you don’t need to start cutting or trimming for them to fit. However, there are a few exceptions where we deliberately make the windows a little bigger in order to fit where body trims are bonded to the glass, but we can not add them to the polycarbonate - for example, some front and rear door 1/4s that have metal work attached from the factory, we leave bigger so they can be fixed directly to the inside of the doors.


Are they road legal?

Our Clear and Clear Hardcoated lexan polycarbonate windows are UK road legal in all sides. Our Grey and Bronze tint windows are UK road legal in rear screens ONLY.


My glass windows have black borders, do yours?

YES – if there’s a black border on the stock glass we put one on the Polycarbonate, and usually you will see we put the dot matrix on and any other detail just to make the windows look sweet.


Can I fit the door windows to the electric motors?

YES – as our windows are direct replacements for the glass they will fit to the electric or manual winder mechanisms, however we recommend you choose the hardcoated polycarbonate as regular polycarbonate will scratch very easily. They don’t come with any of the window fitting tabs or fixings though.


How do your windows fit?

There are 2 ways that windows are usually fitted to cars:

On older cars, which use rubber seals / gaskets, our windows fill be a direct fit into these just like the stock glass.

On newer cars, where the windows are bonded in, our windows will just simply bond back in using the correct adhesives.


What do I stick them in with?

IMPORTANT – Do not be tempted to use any glues or primers that are designed to bond glass windows into cars. These primers and cleaners are too aggressive for polycarbonate, and the typical glass adhesive does not allow for expansion in the polycarbonate. These will damage your windows.

Use our Sikaflex adhesive -or an alternative high elastic urethane adhesive- and there is no need to add any additional primer to the polycarbonate.

TIP – Don’t let your windscreen fitter try to tell you any different!

  glass adhesive damage glass adhesive damage 

Glass adhesive does not allow the polycarbonate window to expand and will either rip of the print or primer with the damage that you can see 


My doors are frameless, how do I fit the windows?

Frameless door windows suffer from flexing at the top and rear side (B pillar), so really you need to add our rolled alloy stiffening plates which fit to the back edge of the windows and allow you to add fixings into the metal work of the door.  

TIP – if you want to roll the windows up and down, we recommend choosing 5mm thick ‘hardcoated’ polycarbonate without the stiffener plates. If you are fixing the windows solid you can go for a thinner polycarbonate 4mm with the additional stiffener plates.


How do I look after them?

Just use our POLYPOLISH window care kit.

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