The only reoccurring type of transformers dream I have is the old "Find a cache of 'new-old stock' G1s (including "rare" ones that never actually existed) in some dinky little store in the middle of nowhere"...
...although one time I had a nightmarish kind of thing where a very "realistic" Shockwave was laying waste to stuff, trying to murder me... and I was trying to get away, just managing to stay hidden behind various objects... the dream ended (via my waking up with a jolt) with the last hiding place (a burned out building-y thing) getting blasted away - and ol' Shockie taking aim...
It was quite a doozy!