1: Oscillating crystal perhaps not so rare (9)
2: One later enters, like, with matching sides (11)
3: Show off Mark's Mazda Miata, for one (6,3)
4: Neil Armstrong initially brought back extraterrestrial (5)
5: He wrote a bit of poetry! (3)
6: Notes spent in Germany (5)
9: Quiet decor back, embracing open encouragement to move forward (7)
12: Martyr fighting segregation (5,6)
15: Cuts in hospitals cause reorganisation of top trauma. (9)
16: Omission in error is no lie (7)
17: Tess spied wrinkled skirts (9)
20: Roosevelt's undergarment? (5)
21: No right to secret desire (5)
22: Freeze one mug filled with tea, essentially (3,2)
24: Three kernels of copper-yellow grain (3)