As I mentioned to Audrey, the context tells us nothing about the possible location. The text merely says that someone is fixing one of these to a car. It's a complete aside.
Can we see it in its context? Maybe the term is not being used correctly in German. Is it visible from outside the car or is it under the bonnet/hood? What is being said about it? Enough questions for now.
Automatic update in 00:
Answers
20 mins confidence: peer agreement (net): +5
radiator lip
Explanation: or: lip of the radiator
would be the mirror translation
Without a source text or context to go by, this is admittedly a shot in the dark ;-)
Audrey Foster United States Native speaker of: English PRO pts in category: 15
Grading comment
Thanks!
Notes to answerer
Asker: Sorry, the source and context are no help whatsoever because the text only mentions that someone is fixing one of these to a pimped car.