I think dreams are fascinating. Sometimes I can find some unconscious fear or hope in my dreams. Often I can see how a word I used the day before is interpreted by my mind in a completely different way and a weird dream is generated. When I was a kid I sometimes used to plot out interesting dreams before going to sleep.
I don't often put any serious weight into dream interpretation, although once in a while I find a weird fear I wasn't expecting.
Could your dream just be generated by some combination of words that put together your friend and the theft?
I can't see how there could ever be a systematic process for interpreting dreams because they seem to be generated in very different ways.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13