I see more and more vehicles with red lit letters on the rear – the latest from Peugeot & Škoda. Why red? According to UN R48 and R148. the only possibility for rear lit logos in Europe to have them as part of the position lamps, which are red, with a maximum logo size of 100 cm2. R148 says:
4.5.6. On request of the applicant, the internal structure of the optical components and/or the texture of the outer lens inside of the apparent surface of a lamp (function) may incorporate only one manufacturer logo build by transparent or non-transparent components provided that all requirements for the specific function of this Regulation are fulfilled and in addition the following conditions:
…
(b) Size: the enclosed light emitting surface of the logo (incorporating transparent and non-transparent components of the logo) of such a lamp in the direction of the reference axis shall not exceed 100 cm2.
…”
There is still a grey area in the text to define this surface, especially when you have such lit letters. Should it be the minimum quadrilateral shape, should we take into account the surface between the letters…? This discussion is still pending among the countries who are Contracting Parties to the UN Regulations.
Here’s an extract from GTB documents with different interpretation of the current text, yielding different results: (extract of GTB document GTBWGSL545 Rev1)
During DVN Munich I took time to measure the logo size to check different methods (A-B-C-D) like above.
I think the first lit logo in Europe was on a Porsche – introduced as an unlit callout, and subsequently given light:
Opel’s first lit callout was on the Grandland:
(British sister brand Vauxhall has the same brand identity):
The Jeep Compass:
Alpine’s first was on the A390:
Toyota’s first lit callout was on the C-HR:
Lexus started out with the ES 500e:
Audi introduced the feature on the A6, and then the Q3. Only with rings in Europe…
…but in China they lit up the letters for the new audi brand:
China’s regulation is different: when the vehicle is parked, you can have a white-lit logo on the rear. And while driving, there is no maximum size for the lit logo. That creates more styling flexibility. Here’s the Great Wall Haval:
Nissan Frontier and NX8:
BYD (typefying most new cars at the Shanghai Auto Show 2025):
Roewe (concept):
Aito M5:
Zeekr X and 009:
To take maximum advantage of the allowances in the Chinese regulation, Lynk & Co developed for their 900-series a brand callout which can light up in red and in white, the first on the market:
As to the technology, the optical concept is usually simple. For example, direct LED + milky lens as on the Aito M5.
Another way to do it is indirectly, as with white metalized box + milky inner lens as on the Zeek X:
