Turn signal warning

[marbique]

I have a 2001 Boxster S I bought new. I'm new to this site (and it's a great one, one of the best I've seen - already found answers to 3 of my 4 questions and managed to spend $400+ in less than an hour on various links.)

The question I haven't found any comments on is this: Maybe it sounds stupid - I'm not that stupid, or if I am, I have encountered at least a handful of other guys like me - but has anyone come across a switch or other device that will sound an audible warning after your turn signal has been on for, say, more than a minute or so? With the roof down and bright sun blanking out the green indicators in the dash, it is easy not to notice that your signal is still on from a lane change or other manouevre small enough not to trigger the cancel switch when you spin the wheel. Three of my last Grand Cherokees have had a "signal on" warning that comes up in the display screen so it can't be that weird a question. I have developed a sort of habitual twitch where I constantly feel the signal switch to see if it is in the middle (i.e - off) but I would love to install some kind of buzzer or other warning to save me the hassle.

Anyone know of one? (If you do, you don't have to admit to leaving your signal on like me - you can just say you saw one one your wife's / sister's / brother-in-law's car.) Thanks in advance.