When they are in the Rolls going over the bridge, the other cars on the bridge are definitely not 1962 model cars. I suppose they couldn't close the bridge (whatever bridge it was), and had to just use a normal aerial shot, and got the modern cars in the process.
BTW, I missed the technobabble. How did they get it so that Blake could see Al?
Is this the "Christmas Carol" episode? If so, that is some technobabble about Blake's brainwaves being close to Sam's.
Is this the "Christmas Carol" episode?
Yes.