My VT wagon seems a bit 'Bouncey'. But I don't mean wallowing like the shocks had gone and they seem ok when I bounce it by hand... it seems really tight and bouncey - like the springs are too strong

I am wondering if it has upgraded springs. It pulls the boat no problem so I wonder if the extra weight is what it needs.

Question is - will new or upgraded shocks be a benefit.

PS it also slides around in the wet. It has cheap 'Diamondback' tyres on - are these purely to blame or could that be the shocks/spring combo fault too?