My sister even solved it! She also cued on the cake reference, Googling Donna Summer, ending up on a hobby shop page listing of Rapido Trains E-series cars. Both she and Jakob enjoyed, but were not fooled by the red herring sleeper names. Just for the record, there was definitely no car named 'Eltonjohn'. Ian Lisakowski also guessed correctly. Kelly Corbett relied on the internet, no Trackside Guide required and came up with the correct response.
Thanks to everyone for your replies. You get an 'E' for Effort, Extreme Efficiency, Efficaciousness and Exemplary Exactitude. Excellent! Also, thanks for all the comments and good wishes on Trackside Treasure's fourth!