Depends which circuit they are running as the majority of it is off limits to the public.
Options
1. Top of the circuit Peel corner is good for straight on shots plus three quarter pans. You can also do shots of the backs of the cars going towards the Sea if you turn to your left as they go away from you.
2. Corner 1 is a tight left past the pit wall onto a long straight. Opportunities for some sideways exits from the corner plus pans along the straight.
3. If they use the coastal circuit theres a group of 2 corners just above the pits coming downhill (corkscrew). This is good for side on pans plus head on shots coming over the hill.
4. If they use the International circuit then you also get the tight hairpin. Not the best spot in my opinion as you are looking down at the cars.
Anglesey circuit config link
Shameless plug
Pics from Wirral 100 at Anglesey last year link. Selection taken from all the options above except 4 as they use the Coastal Circuit.
Hope this helps.
Steve