When my MK4 is hot it wont start like the battery is flat its had a new starter but still the same, also it misses when you first get it started

here's my prob, i have a white mk4 xr3i cab, full rst kit and i'm thinking of the following :   matt black paint   cossie arches   wrc front and back   60mm drop   17' multi spoke (white or black)   clear rear lights   badboy bonnet   just looking for some feedback good and bad views wanted, lol.   if anyone could post pics of a mk4 with the wrc/cossie kit on it, this would be great.   cheeRS

Please help i have just been filling my car up at petrol station and key snapped in lock any sugesstions??