Across:
   8. Come down heavily with heartless vain fellow (4)
   9. Number one model car with dry and primarily retro appeal (10)
  10. Yin's partner has time with Zoe on vacation in one of China's 22 in 14 in '98 (7)
  11. Something leaking through with start of textual cross reference? (7)
  13. Very happy finding safe harbour in troubled gulf (7)
  15. Calm using briefly more than one psychedelic drug (6)
  16. Oligarch's hip "tub" battered in weather system that could make it really 8! (11 4)
  19. Complained: quiet not quiet enough for getting enthralled (6)
  21. Hospital has sicker one brought in, having more ups and downs (7)
  23. Thus new girl helps us appreciate sources for one of China's 22 in 14 in '98 (7)
  25. Imprisoned in modified pit in underground chamber (7)
  28. Feed streams where data's collated (10)
  29. Standard of either nasal letter? (4)
Down:
   1. Dropped line in ploy with a new girl in Chinese 5 in 14 in '98 (6)
   2. Piece of rag men try to grip? (8)
   3. Some of its pieces are old rags, like jeans and zig zagged tops (4)
   4. Pen missing last letter from one of the 22 of Hades (3)
   5. Girl, a keeper, keeping Greg on bass guitar (4)
   6. Thai pot U-turn mostly making for a happy place? (6)
   7. Doting around new girl in Chinese 5 in 14 in '98 (8)
  12. New girl in unusual hat is fine (7)
  14. Vital supplies interrupted by large disaster (5)
  15. Soft fruit left in one of China's 22 in 14 in '98 (5)
  17. Troop, due to move, moved abruptly (8)
  18. Arranging go in this can be uplifting (8)
  20. Possibly Chinese building base, one using ancient game of strategy (6)
  22. Whanganui, Mata-Au and Waiau Toa, perhaps, in Maori version (6)
  24. Headwear you briefly turned around, as some of America (4)
  26. Too aggressive, like some older leaders (4)
  27. At heart, eminently one of China's 22 in 14 in '98 (3)