Hi Please can someone help. I can't afford a mechanic and usually do the little bits myself. I changed oil and filter  as the car had too much oil in it when I bought it. It went into limp mode so purchase the spray to put into the diesel filter underneath. Took the car for a long drive at 3000rpm the engine malfunction stayed off for a while abd occasionally would come on and go Into limp mode. After heavy rain the indicators came on when car was off them power steering malfunction came on abs now all lights and won't start. I spoke with my dad he says the leak I. My window screen above mirror has leaked into the computer. Under gearstick. I've  looked and can't find it can  someone please point me in the right direction so I can fix this car please  thank you for your time 

First question, are you in the UK ?

Second question is the car RHD ?