After recently trying to track down an oil leak (resulting work was camshaft oil seals replaced, rocker cover gasket replaced, timing belt change, camshaft change, full set of rockers replaced plus rocker gaps all done in an afternoon by Simon at Contract Mechanics - great guy, great job - really recommend him and I won't be going anywhere else), I removed the undertray for easier tracking down of said leak. After degreasing, scrubbing and deep cleaning, I am now left with the undertray in two halves. I am due to fit it tomorrow, do I need to join the two halves together first and refit as a whole piece or can I fit the individual pieces and if so which bit goes on first?
I realise I should have thought of this and remembered how I took it off in the first place but age and memory is getting the better of me these days

Any thoughts?
Cheers
Mark