I parked my car within walking distance of T4 when I went to Australia for 3 weeks in August. But I did pay the fiver to drop off in front of the terminal, and then it took half an hour to get back. Obviously I didn't take up space that a resident would normally use. No problems except it was covered in spiderwebs when I got back because there are spiders living behind my mirrors. There is also a lot of free parking along the 203 bus route, and it's now free to take the tube from Hatton Cross.