Drive vehicle up into lighthouse - that's a bit wicked (7)
I believe the answer is:
knavish
'wicked' is the definition.
(thesaurus)
'drive vehicle up into' is the wordplay.
'drive' becomes 'kish' (I can't explain this - if you can you should give a lot more credence to this answer).
'vehicle' becomes 'van' (van is a kind of vehicle).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'into' is an insertion indicator.
'van' back-to-front is 'nav'.
'kish' placed around 'nav' is 'KNAVISH'.
'lighthouse that's a bit' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for knavish that I've seen before include "like a rogue" , "Full of dirty tricks" , "Dishonest, unscrupulous" , "like one able to beat ten?" , "Wily" .)