Well, I just found the street view for 3 houses in Bristol. Maybe some of the houses you tried to view are in locations where the Google Car has not been.
As for trains,
(1) one that I found myself is a Mitcham Eastfields station in South London
Use Street View and you can rotate the camera, and move along Grove Road and see more of the train, which is a Class 319 electric multiple unit belonging to First Capital Connect.
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Mitcham+Eastfields+railway+station,+Merton,+United+Kingdom&sll=48.856667,2.350987&sspn=0.357353,1.056747&ie=UTF8&hq=Mitcham+Eastfields+railway+station,&hnear=Merton,+Greater+London,+United+Kingdom&ll=51.408335,-0.15089&spn=0,0.016512&z=17&layer=c&cbll=51.40844,-0.153723&panoid=oe0Mqt58Ld0jUMJ8Rx7k_Q&cbp=12,241,,0,1.73
(2) Lots of links in this Google Groups thread
http://groups.google.com/group/uk.railway/browse_thread/thread/d0e203da9077a1f7/83752f81a747e7bd?q=google+streets+trains&lnk=ol&