Need some help with these....
47a. Spooner's guide to impassably wet roads that's useful on a lorry - MUDFLAP but I can't see an apt Spoonerism.
17a. One tampering with sound rose tree (7) - MEDDLER? fits but I can't parse it.
Leave to introduce priest, an old stager - CONGREVE - I know who he is but can't see the wordplay.
5d. A series of radar impulses across the deck (5) - ABEAM? Wht 'Radar Impulses'?