1: Perhaps stonefish can be found in shamrock code. (7)
2: After Friday, Luke gets a piece of tail? (5)
3: Auto manufacturer meeting a lieutenant in 'The Ancient Mariner'? (3,4)
4: Trailer crashed in second test (7)
5: Figure it can go to pieces (7)
6: Strange nectars induce dreamlike states. (7)
7: Grant authority to gaucho, finally, packing whip for farm animals (9)
8: Unscripted part for head librarian (2,3)
14: If forced, see idle TV broadcast (9)
17: Choice bergamot subdues growler (7)
18: Thirteenth in a series, ER's about an Aussie racketeer who took repeated slams? (7)
19: 'Observe!' I cry to the audience (7)
20: Dopey met hero with a proposition (7)
22: Supremely clever stories, overlaid with humor (7)
23: Navigate by terse directions (5)
26: Practise using public transport (5)