Rennenglas Heated Windscreens are used by every top racing team in every category of racing to keep the front windscreen fog free during a wet race.


Heated windscreens utilize the same super reliable technology as the heated windscreens available on some models of standard road cars sold in cold climates.
They are quite efficient. The standard heated windscreen on a Ford Mondeo can melt a decent layer of frost in about 2 minutes and keep it fog free.

How they work:

Modern safe automotive front windscreens are made from laminated glass. Two pieces of glass are curved as a pair in a furnace then bonded together with sticky heat or UV activated plastic (Interlay) between them.
The interlay may contain various features, a top tinted band or a radio or GPS antenna. If the windscreen is to be heated almost invisible Micro tungsten heater wires are embedded in the interlay.

Some have one element but most left and right elements. 20 amps required for each element. Wires come out the bottom on each side. Click here for wiring instructions

WOF and RAC (Road Authority Card) compliant. Fully street legal.

Rennenglas Heated Windscreens are made to order in batches of 5 by various plants around the world depending on where the particular model’s glass tooling is located. We keep stock of popular models and offer them for sale individually. Click here to go straight to our Heated windscreen store.

If you don’t see your vehicle listed give us a call and we may have one and just have not listed it yet or we can get it in for you.

If you have a unique vehicle, we can get tooling made and a one-off heated windscreen manufactured for you. If you know a few people with the same car and we get more interest we will get 5 made and that will bring the cost down.

Where does the fog come from?

Fog is formed on the inside of your windscreen when the air on the inside face is hotter than the air on the outside and there is water in the car. Water in the car (in puddles on the floor, absorbed in your race suit or boots or seat, or in the moist air itself) evaporates and then condenses on the inside face of the windscreen.
Once it forms it is difficult to get rid of.

To reduce fogging up your windscreen:

* Keep your race suit and boots dry when you are out of the car. Put towels down where the drivers stand during driver changes.
* Keep or fit aircon in your car.
* Keep the factory heater / demister.
* install a 12v bilge blower and point some hose at the important areas of your windscreen
* Don’t throw away the original door or window seals and keep the windows up
* Tape up any holes in the cockpit to stop water getting in.
* Get a piece of broom stick and tape a rag on the end or a squeegee so you can reach the windscreen while you are driving
* Rainex the inside of the windscreen (before it gets wet)

Or just buy a Rennenglas Heated Windscreen

Give us a call on +6492789816 or send an email to [email protected] so we can discus the solution to your problem.



Rennenglas. With our world wide network of suppliers can supply a standard windscreen for any car or create new tooling for out of production products.

Give us a call on +6492789816 or send an email to [email protected] so we can discus the solution to your problem.


Rennenglas Plastic Windows are available in a range of materials and configurations depending on the end use and function.

For the type of club racing that most of us do in New Zealand on balance of safety first then cost we recommend these materials in these positions:

  • Door glass Flat, 3 mm MR10 hard coated polycarbonate
  • Door glass moulded, 3 mm standard polycarbonate
  • Rear ¼ Flat, 3 mm MR10 hard coated polycarbonate
  • Rear ¼ moulded, 3 mm High impact acrylic
  • Rear hatch flat, 3 mm MR10 hard coated polycarbonate
  • Rear Hatch moulded, 3 mm High impact acrylic

We have CNC drawings and moulds for most windows used on race cars in NZ. We make to order so just give us a call +6492789816 or drop us an email [email protected]

If the vehicle must be road legal and have a Warrant of Fitness (WOF) or Road Authority Card (RAC) then all the windows should be hard coated polycarbonate. You will see the requirement quoted as “MR10” or “AR10”. These are brand names for Mar or Abrasion resistant hard coated polycarbonate sheet. MR10 and AR10 come in flat stock sheets and it cannot be moulded because the coating will crack and craze.

Sheets are big, 2 x 3 metres. We can supply you with a smaller piece big enough for you to cut your flat window out of or for the same price we can CNC cut it to the final shape of the window for you. We have cut files for most windows or we can digitize your glass or patterns.

If your windows need to be formed or moulded to fit the car better we can supply formed and hard coated windows. Hard coated polycarbonate is by far the best material but it comes at a cost and takes several months to produce and the windows must be imported so there is a freight cost as well.

We make to order so just give us a call +6492789816 or drop us an email [email protected]


This is the type of product we make most. This product is a Mazda RX7 FD3S Competition Rear window (FRP hatch not included)

  • This part is moulded high impact acrylic
  • The black band is optional and extra

This material is the best compromise for the New Zealand market.

  • It is not strictly street legal.


  • It is much stronger that standard acrylic
  • The surface is is almost as scratch resistant as MR10 polycarbonate.
  • UV protection is very good
  • The same material is use for OEM headlights and OEM competition car glazing.

We can produce this product in polycarbonate but although polycarbonate is very strong the surface is very soft and will scratch very easily. Your helpful crew will inadvertently scratch it just by wiping it once with a rag.

It is available in hard-coated Polycarbonate but the lead-time is great.