English to Latvian Tech/Engineering Automotive / Cars & Trucks

From a description of a city/intercity passenger bus. It may be that the English source text is written by a non-native English speaker, so I was wondering if it could be related to towing or similar, but still couldn't come up with any likely guesses.

Example sentences:
Trailer runners under the front corners and rear corners.
Trailer runners under the front corners are fitted as standard.