Interesting shots you got there but can't help but to agree with the rest. The better way to portrait out the head and tail lights streaking effect is to take it from a higher angle or perspective. But the attempt overall is good. I did saw some photos before taken at normal elevation and the effect is still stunning so I believe yours can be further improve.
For #2, the street light appears quite glaring, a suggestion is to use some filters to lessen the effect or use a 6 point Starbust filter to make it more creative. Overall, good attempt.
set to Manual (not MF), select BULB shutter speed (beyond 30 secs), use an apperture between f19/22 and a remote to shoot for about 20 secs. you should get a nicer shot, although light streaks would look "thinner". but the smaller apperture also reduces the flare pic 1 seems to suffer. looks like there was some tripod shake too? pic looks a little oof. beware of roads with heavy vehicles as these can cause serious vibrations even on the pavement where you're standing.