A 'smart box' that fits neatly into a car's engine bay promises to cut emissions by up to 80 percent and improve fuel efficiency, according to its makers. Matthew Stock reports.
02:40
02:44
02:14
01:39
02:09
01:19
01:34
03:01
01:19
01:51
03:13
01:44
02:04
01:53
02:14
01:13
01:05
01:54
01:21
01:50
01:15
01:44
01:31
01:07
01:27
01:13
01:14
00:51
01:15
01:24
01:27
01:20
01:51
01:30
01:14
01:36
02:12
04:24
01:29
02:14
01:29
02:06
01:21
02:23
01:01
00:58
03:28
02:49
01:37
02:07
00:59
00:39
01:30
00:58
00:54
02:27
01:39
01:02
01:46
01:09
01:36
01:34
01:58
02:07
01:35
01:53
01:04
01:08
01:17
02:01
01:37
01:12
02:31
02:20
03:14