how about cab floor and wheel arches inside , steps inside,

also check the rear axle most are noisy they will stay like that for ever! gearbox is normaly strong, now the v4 ,you need to rev it up and check for blue smoke ,then play with the throtle of the engine to see if you can here any grumbling from the bigends ,these engines are well known for crank problems also if the engine had done over 60-70k and is in good helth it will be needing a oil pump driveshaft soon ,these ware over time and go without any warning as soon as the oil light comes on its more or less to late!
head gaskets were a problem also ,so take the oil cap off and check for sludge (whitey creamy mixture) and pull the dipstick and make shure its only got oil on it! not sludge!
they are a easy engine within reason to keep and most jobs can be done with the engine in the van! alot of poeple hated them but if you had a good one and looked after it regular oil changes etc they were great ! well i never had that much problems with them anyway! .mark